This low FODMAP green bean casserole brings all the creamy, cozy comfort of the classic holiday side without the garlic, onions, or dairy. It's completely gluten free, made with fresh green beans and a simple homemade sauce instead of canned soup. It's perfect for Thanksgiving or any holiday dinner where you want that nostalgic flavor in a gut-friendly way.
If you're planning a full low FODMAP holiday menu, I've got you covered with plenty of side dishes that everyone will love. Try my low FODMAP stuffing and low FODMAP cranberry sauce - both gluten free and dairy free - to round out your Thanksgiving spread. Each recipe is packed with flavor, so everyone at the table can dig in and enjoy, even if they aren't following a special diet.
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Why You'll Love This Recipe
- Total comfort food vibes. Creamy, cozy, and baked until golden. It tastes just like the classic, only gentler on your gut.
- No mystery ingredients. You'll skip the canned soup and build a quick homemade sauce that's gluten free, dairy free, and so good you'll want to lick the spoon.
- Holiday perfection. It fits right in on your Thanksgiving table and pairs beautifully with turkey, mashed potatoes, and cranberry sauce.
- Family-approved. No one will even realize it's low FODMAP.
What You'll Need
- Green Beans - Fresh, frozen, or even canned all work here. Just make sure they're plain with no added onion or garlic.
- Dairy-Free Butter - Any plant-based butter that fits your diet works great.
- Gluten-Free Flour - I like Bob's Red Mill 1-to-1 Gluten Free Flour (the light blue bag) for easy thickening.
- Chicken Broth - Choose one that's free from gluten, garlic, and onions to keep this recipe truly low FODMAP. Chicken stock works too.
- Unsweetened Almond Milk - Stick with unsweetened so your sauce stays savory.
- Coconut Cream - Gives the sauce that rich, creamy texture without any dairy.
- Mushrooms - Canned mushroom pieces are the best low FODMAP option. Drain and rinse them well before adding.
- Black Pepper - Adds a little warmth and depth to the sauce.
- Gluten-Free Soy Sauce - Build that umami flavor.
- Shoestring Potato Chips - The perfect crunchy swap for fried onions.
- Nutritional Yeast - Adds a subtle cheesy flavor to the potato chip topping.
See the recipe card for the exact measurements and complete instructions.
Selected ingredients are based on guidance on current serving sizes measured by the Monash University Food App and FODMAP Friendly App at the time of publishing. As always, follow your gut and modify as needed.
Step-by-Step Instructions
Step 1: Preheat and Melt
Preheat the oven to 350 degrees F. In a large skillet over low to medium heat, melt the dairy-free butter to start the homemade mushroom sauce.
Step 2: Add the Flour
Sprinkle the gluten-free flour over the melted butter in the skillet.
Step 3: Whisk the Roux
Using a whisk (a flat whisk is my favorite) whisk the butter and flour together until smooth.
Step 4: Add the Broth
Pour in half of the chicken broth and whisk. It will look clumpy at first. Keep whisking, then add the remaining broth and whisk again until it starts to look like a sauce.
Step 5: Stir in Almond Milk
Whisk in the unsweetened almond milk until the sauce is smooth.
Step 6: Finish the Creamy Base
Add the coconut cream and whisk again until the sauce is silky and lump-free.
Step 7: Season and Add Mushrooms
Chop the mushrooms if you prefer smaller pieces. Add the mushrooms, gluten-free soy sauce or coconut aminos, and black pepper. Whisk to combine, then turn off the heat.
Step 8: Combine With Green Beans
Grease a casserole dish. Add the partially thawed green beans and pour the hot sauce evenly over the top.
Step 9: Crisp the Topping
Line a baking sheet with parchment for easy cleanup. Spread the shoestring potato chips in a single layer and sprinkle evenly with nutritional yeast.
Place the casserole and the topping in the 350 degrees F oven. Bake the casserole for about 30 minutes or until bubbly, and bake the shoestring potatoes for about 20 minutes or until crispy and golden.
Step 10: Top and Serve
When the casserole is done, sprinkle the crispy shoestring potatoes over the top and serve right away.
Tips and Tricks
Make-Ahead Tip: If you aren't serving the casserole right away, wait to bake the shoestring potato topping until just before serving so it stays perfectly crisp.
Whisk, Whisk, Whisk: The key to a silky sauce is steady whisking after each liquid addition. It gives you that creamy, from-scratch texture. If it gets too thick, add a splash of broth to save the day!
Fresh, Frozen, or Canned: Any green beans work here. Just drain and pat canned beans dry before adding to avoid extra moisture.
Special Diet Variations
Vegan Gluten-Free Green Bean Casserole: Swap the chicken broth for vegetable broth to keep it vegan while still rich and flavorful.
Gluten Free Stuffing Green Bean Casserole: Layer your favorite gluten free stuffing on top instead of the shoestring potatoes for a cozy mash-up that tastes like two holiday favorites in one.
Skip The Mushrooms: Not a mushroom fan? Leave them out. That's the beauty of a homemade sauce, where you control the ingredients.
Alternative Toppings For Green Bean Casserole
Traditional fried onions aren't gluten free or low FODMAP since they're usually made with wheat flour and onions. The good news is there are plenty of crunchy, flavorful alternatives that give you that same golden topping without the tummy troubles.
- Shoestring Potato Chips - Crispy, salty, and the perfect easy swap for fried onions.
- PopCorners Sea Salt Corn Snacks - Love these as a snack, but they also make a great crunchy topping when crushed.
- Crushed Plain Potato Chips - A quick and easy option that adds that classic salty crunch.
- Crumbled Pork Rinds - Adds a savory, crispy bite and extra protein, all while staying gluten free and low FODMAP.
- Toasted Almonds - For a lighter, nutty topping that still adds texture and flavor.
Storing and Reheating
Store: Keep any leftover green bean casserole in an airtight container in the refrigerator for 3 to 4 days.
Reheat: Warm leftovers in the microwave until heated through. For that fresh-from-the-oven crunch, toast a new batch of shoestring potatoes and sprinkle them on top before serving.
Freeze: Freezing isn't recommended. The sauce can separate during freezing and thawing, and the texture just won't be the same.
Low FODMAP Notes
Low FODMAP ingredient information is based on the Monash University Food App and FODMAP Friendly App testing results as of the day posted. As always, modify based on your gut and what works for you on a low FODMAP diet.
- Green Beans: Monash University lists fresh green beans as low FODMAP at up to 75 grams (about 15 beans) per meal. That makes this casserole a great veggie side for those following the diet.
- Mushrooms: Use canned mushroom pieces, drained well. Canned champignon mushrooms are low FODMAP in small portions (about 6 pieces per meal). Avoid fresh button, portobello, or shiitake mushrooms.
- Chicken Broth: Check the label to make sure it's free of garlic, onion, and gluten. These hidden ingredients are common FODMAP triggers.
- Dairy Free Butter: This is great option if you need dairy free, but real butter is also a great low lactose ingredient.
- Coconut Cream: Love using this for a creamy dairy free option. It is safe up to ¼ cup (60 grams) per meal.
- Unsweetened Almond Milk: Low FODMAP in servings up to 1 cup (240 ml). Always choose unsweetened to keep the flavor savory.
- Gluten Free Flour: Keeps the sauce thick and smooth without adding any FODMAPs. A 1-to-1 blend like Bob's Red Mill works perfectly.
- Soy Sauce: Add umami flavor, but always choose a gluten-free brand to stay 2 tablespoons (42 grams) per meal.
For additional information on a low FODMAP diet, please visit Monash University or FODMAP Friendly. Both have websites and apps for additional guidance and testing results.
FAQs
You've got questions, I've got answers!
Yes! Monash University has tested fresh green beans to be low FODMAP at about 15 beans or 75 grams per meal. As always, test your own tolerance and listen to your gut.
No, traditional cream of mushroom soup contains high FODMAP ingredients like garlic, onion, and milk. This recipe uses a homemade lactose-free sauce instead to keep it creamy and gut friendly.
No, most traditional recipes contain high FODMAP ingredients like onions, garlic, cream of mushroom soup, and wheat flour. This version skips all of those while keeping the same creamy, comforting flavor.
Not all types are. Canned mushrooms are considered low FODMAP in small portions (about ½ cup per serving), while fresh button, portobello, and shiitake mushrooms are high FODMAP.
Try shoestring potato chips, crushed gluten free crackers, PopCorners Sea Salt Crackers, crushed plain potato chips, or toasted almonds for a crunchy topping that's gluten free and low FODMAP. Each adds texture and flavor without the onions.
Yes. Simply use vegetable broth instead of chicken broth, and be sure your butter and milk alternatives are plant-based.
Absolutely. Assemble the casserole up to 24 hours in advance and refrigerate. Bake the topping right before serving so it stays crispy.
Keep leftovers covered in the fridge for up to 4 days. Reheat in the microwave or oven until warm, and toast new shoestring potatoes for that fresh crunch.
What To Serve With Low FODMAP Green Bean Casserole
This low FODMAP green bean casserole isn't just for the holidays. It's a great weeknight side dish too. It's so good my son even requests it for his birthday dinner, and honestly, I don't blame him. Serve it alongside low FODMAP stuffing, low FODMAP mashed sweet potatoes, and low FODMAP cranberry sauce for a full Thanksgiving spread that's completely gluten free, and gentle on the gut.
More Loveable Side Dish Recipes
- Roasted Delicata Squash - Sweet, caramelized, and perfectly tender. The easiest side to brighten up any fall meal.
- Almond Milk Mashed Potatoes - Creamy, fluffy, and completely dairy free. The ultimate comfort side for any dinner.
- Spinach Salad With Maple Dijon Dressing - Fresh baby spinach tossed with bacon, cranberries, feta, and mandarin oranges for a sweet and savory salad that goes with everything.
Still looking for the perfect side dish recipe? Discover something new or find an old favorite!
Love This Recipe?
Leave a ⭐⭐⭐⭐⭐ rating + comment. It helps so much, and we love hearing from everyone! Thank You -Venessa
Recipe
Low FODMAP Green Bean Casserole
Ingredients
- 12 ounces frozen green beans, cut or fine (Note 1)
- 3 tablespoons dairy free butter
- 3 tablespoons gluten free flour (Note 2)
- 1 cup low FODMAP chicken stock
- 1 cup unsweetened almond milk
- ½ cup full-fat, unsweetened coconut cream
- 4 ounces mushroom pieces canned and drained
- 1 teaspoon freshly cracked black pepper
- 1 tablespoon soy sauce gluten free, (Note 3)
- 2 cups shoestring potatoes
- 2 tablespoons nutritional yeast
Instructions
- Preheat oven to 350 degrees F.
- In a large skillet, melt the dairy free butter on low to medium heat to make the homemade mushroom sauce.
- Once melted, sprinkle the gluten free flour over the melted butter.
- Whisk together the melted butter and the flour. A flat whisk works well.
- Once the butter and flour are completely combined, add half of the chicken broth. Whisk the broth into the flour mixture. The broth will hydrate the flour and form clumps. It is ok. Keep whisking. Add the other half of the broth and whisk again. The mixture will begin to look like a sauce.
- Next, add the unsweetened almond milk to the skillet. Whisk into the sauce.
- Once the almond milk is mixed in, add the unsweetened coconut cream. And whisk again.
- Add the chopped mushrooms, soy sauce, and black pepper to the creamy sauce. Whisk it until all combined. Turn the heat off.
- If using frozen green beans, heat in the microwave for three minutes to thaw a bit. If using fresh green beans, snip off the stem end and wash thoroughly.
- In a greased casserole dish, add the partially thawed green beans and pour the sauce over them.
- On a baking sheet, lay down a sheet of parchment for easy cleanup. Next, spread the shoestring potatoes in a single layer. Sprinkle the nutritional yeast evenly over the shoestring potatoes.
- Place the green beans in a baking dish on an oven rack and the shoestring potatoes in a preheated 350 degree F oven. Bake the green beans for 30-35 minutes or until bubbly. Bake the shoestring potatoes for 20-25 minutes or until crispy brown.
- Once the green beans are done baking, sprinkle the shoestring potatoes over the top and serve immediately.
- If you are not serving the green bean casserole immediately after baking, wait until just before serving to bake the shoestring nutritional yeast mixture and add just before serving. The green bean casserole can be prepped the day before and reheated to save on oven space. Keep the shoestring potato mixture and the green bean casserole separate until serving. The shoestring potatoes will get soggy.
- Keep any leftovers in an airtight container in the refrigerator for up to four days.
Venessa Mandelkow says
Made this for a side dish and there were no leftovers! Added additional shoestring potatoes because I love them!