This Low FODMAP* Instant Pot Ratatouille (pronounced ra-tuh-too-ee) is a low FODMAP version of a classic French vegetable stew that's healthy, hearty, warming, and delicious. Easier to make than you might think, this low FODMAP ratatouille recipe will get a nutrient-rich, tummy-friendly main dish on your table in less than 30 minutes! In addition to being low FODMAP, this ratatouille recipe is Keto, low carb, Paleo and Whole30 compliant, vegetarian, and vegan. Serve it over my low FODMAP polenta (not Keto, low carb, Paleo, Whole30 or vegan) or your preferred starch option for an even more satisfying meal.
*Please note: some of the ingredients in this recipe have been retested for FODMAPs by Monash University after this recipe was originally posted. Check Monash University's Low FODMAP Diet App for the most-up-to-date FODMAP information and research.
What is Ratatouille?
You may have heard of ratatouille before, most likely through the popular animated film of the same name featuring a cartoon rat. My low FODMAP ratatouille has nothing to do with rats (thank god); rather, with a classic French vegetable stew hailing from Nice in France's province of Provence.
Historically, preparation of ratatouille has ranged from extremely fancy and complex to more simple and rustic. This low FODMAP Instant Pot version of ratatouille is on the simple, rustic end of the spectrum and still tastes freaking amazing. Full of flavorful herbs and tender crisp vegetables typically harvested in late summer, ratatouille is surprisingly addictive.
Low FODMAP, Keto, Low Carb, Paleo, Whole30, Vegetarian, and Vegan
When I first discovered ratatouille, I was skeptical. A meat-and-potatoes kind of gal, I didn't think a vegetarian and vegan main dish featuring only low FODMAP vegetables and herbs could win me over.
Boy, was I wrong.
And, when served over polenta - wow. These two dishes come together so beautifully to create an explosion of flavors and textures in your mouth. My view of vegetable-forward recipes will never be the same.
While my low FODMAP polenta recipe isn't vegan, you can also serve this ratatouille over rice or something of that nature to keep it entirely vegan. Or, you can try making the polenta vegan by omitting the cheese and using olive oil instead of butter. I haven't tried it personally, but if you're feeling adventurous, give it a try, and let me know how it goes!
The equipment I use to make this low FODMAP Instant Pot Ratatouille includes:
- 6-quart Instant Pot, 8-quart Instant Pot, or comparable electric pressure cooker
- Chopping knife and board
- Measuring spoons and cups
- Plastic spoon for stirring and scraping
- Serving bowl and ladle
Low FODMAP Instant Pot Ratatouille: Ingredients & Success Tips
Garlic-Infused Olive Oil
To start this recipe, I hit "Sauté" on the Instant Pot. Once the display reads "Hot," I add the garlic-infused olive oil and swirl the pot to cover the bottom in oil.
I use garlic-infused olive oil to add garlicy flavor without the FODMAPs. Since FODMAPs are not oil-soluble, this gives me great garlicy flavor without adding any FODMAPs to my ratatouille.
Then, to add oniony flavor, I add ½ cup of finely chopped, dark green leek leaves to the pot and sauté for 2 minutes, stirring frequently. According to Monash University's Low FODMAP Diet App, the dark green parts of leeks contain the FODMAP mannitol and are low FODMAP in quantities of up to ⅔ cup per serving.
Once the leeks are done sautéing, I hit "Cancel" on the Instant Pot and add the tomatoes and their juices, using their juices to scrape the bottom of the pot clean with a plastic spoon.
For this recipe, I choose to use canned diced tomatoes and their juices. While all of the other produce is fresh, I use canned tomatoes because 1) it's easier; and 2) the canned tomato juices provide sufficient liquid for the Instant Pot to come to pressure without adding any additional liquid. This may not be true for all recipes for the Instant Pot, but I find it to be true for my low FODMAP Instant Pot Chili Con Canada and for this low FODMAP Instant Pot Ratatouille.
Per Monash University, canned tomatoes contain the FODMAP fructose and are low FODMAP in quantities of up to ⅗ cup per serving. A 28 ounce can of tomatoes contains about 3 cups of diced tomatoes.
If you prefer to use fresh common tomatoes (which are FODMAP-free) to keep all of the vegetables in this recipe fresh, you can use 3 cups chopped common tomatoes and their juices + ½ cup water instead.
Herbs & Spices
Once the bottom of the inner pot is clean, I add the following herbs and spices to the pot and stir:
- Dried chives - one of my favorite low FODMAP ingredients!
- Fresh or dried thyme - I typically use dried to keep things easy
- Salt and pepper
- Dried fennel seed - a low FODMAP spice whose flavor pairs perfectly with the dish's other components. Fennel seed also has a wide variety of health benefits including (but not limited to) promoting digestive health. It can be found in the spice isle at most grocery stores.
Then, I add the fresh vegetables (and fruit, considering eggplant is actually a fruit), starting with 3 cups of eggplant. I mentioned in my low FODMAP Instant Pot Baba Ganoush post that I think eggplant is one of the most underrated ingredients out there as it is amazingly delicious and versatile. Per Monash, it contains the FODMAP sorbitol and is low FODMAP in quantities of up to 1 cup or 75 grams per serving.
To prepare the eggplant for ratatouille, I peel its tough but beautifully-colored skin and chop it into 1-inch cubes.
I also add 2 cups of zucchini, unpeeled and chopped into 1-inch cubes. Monash lists zucchini as containing the FODMAP fructans and is low FODMAP in quantities of up to ⅓ cup or 65 grams per serving. This quantity, while not a lot, gives us plenty of zucchini to work with for our ratatouille.
Red Bell Pepper
According to Monash as of the date of this writing, red bell peppers were listed as FODMAP-free (but now they list them as containing fructose - see recipe notes below for additional information), so I added a whopping 3 cups chopped into 1-inch squares to this ratatouille, which is about 2 large bell peppers. Note that bell peppers also contain capsaicin which can trigger heartburn and other issues for some people with IBS.
Once I add all of the produce, I stir the contents of the pot so that the produce is coated in juices and spices. Then, I close the Instant Pot, set the pressure release valve to sealing, and set the timer for 2 minutes. I quick release the pressure once the cooking cycle has completed and open the lid.
Lastly, I add fresh chopped basil and stir the contents of of the ratatouille until thoroughly combined. I also garnish the ratatouille with additional fresh basil leaves, but that's optional.
Serve this low FODMAP ratatouille on its own or over top of my low FODMAP polenta (not Keto, low carb, Paleo, Whole30 or vegan), or your favorite starch option.
This low FODMAP Instant Pot Ratatouille, a classic French stew made with low FODMAP quantities of eggplant, zucchini, leek, and other vegetables, is healthy, hearty, warming, and delicious. Vegan, Keto, low carb, Paleo, and Whole30 compliant. Please note: some of the ingredients in this recipe have undergone FODMAP retesting by Monash University since this recipe was originally posted. See notes below for further information.
- 2 tablespoons garlic-infused olive oil
- ½ cup leek, dark green leaves only, finely chopped
- 28 ounce can diced tomatoes + their juice*
- 2 teaspoons dried chives
- ½ tablespoon fresh thyme or ½ teaspoon dried thyme
- 1 teaspoon salt
- ½ teaspoon ground black pepper
- ½ teaspoon fennel seed
- 3 cups eggplant, peeled and chopped into 1-inch cubes (about 1 medium eggplant)*
- 2 cups zucchini, unpeeled and chopped into 1-inch cubes (about 1 medium zucchini)*
- 3 cups red bell pepper, chopped into 1-inch squares (about 2 large bell peppers)*
- ¼ cup fresh basil, chopped + additional fresh basil leaves for optional garnish
- Chop and prepare all your ingredients before starting to cook.
- Hit "Sauté" on your 6-quart Instant Pot, 8-quart Instant Pot, or comparable electric pressure cooker. Once the display of the Instant Pot reads “Hot,” add garlic-infused olive oil and swirl the pot to coat in oil. Add chopped leek and sauté for 2 minutes, stirring frequently.
- Hit “Cancel” on the Instant Pot. Add can of diced tomatoes and their juice, and scrape the bottom of the pot clean with a plastic spoon.
- Add herbs and seasonings to the pot: chives, thyme, salt, pepper, and fennel seed (reserve chopped basil for after cooking) and stir. Add chopped eggplant, zucchini, and red bell pepper, and stir until evenly coated in liquid.
- Place the cover on the Instant Pot and set the pressure release valve to “Sealing.” Hit the “Pressure Cook” button and set the timer for 2 minutes.
- Once the cooking cycle has completed, quick release the pressure. Stir in the chopped basil.
- Serve the ratatouille and serve it on its own, over low FODMAP Polenta, or your preferred starch option.
- Tomatoes: If you prefer to use all fresh produce, you can substitute 3 cups common tomatoes and their juice + ½ cup water for the canned diced tomatoes.
- Eggplant: Monash University’s Low FODMAP Diet App lists eggplant, which contains the FODMAP sorbitol, as low FODMAP in servings of up to 1 cup per serving.
- Zucchini: contains the FODMAP fructans, is low FODMAP in quantities of up to ⅓ cup or 75 grams per serving. See post above for more detailed FODMAP information.
- Red bell pepper: This recipe was posted prior to Monash University retesting red bell pepper for FODMAPs. While their previous tests reported them to be FODMAP-free, their more recent tests show they contain the FODMAP fructose and are low FODMAP in quantities of up to ⅓ cup per serving. When eaten in combination with canned tomatoes, which also contain fructose, this has the potential for FODMAP stacking. If you are able to tolerate fructose or had no problems with red bell peppers + canned tomatoes in the past, this may not be an issue for you.
- Keto/low carb: keep this Low FODMAP Ratatouille Keto / low carb by serving it on its own or over a Keto / low carb starch option. Polenta is unfortunately not Keto or low carb.
- Serving size: Makes approximately 6 cups total, with each serving coming to ¾ cup per serving.
- Prep Time: 15 minutes
- Time to Come to and Release Pressure: 10 minutes
- Cook Time: 5 minutes
- Category: Dinner
- Method: Instant Pot
- Cuisine: French
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