A traditional rustic Ratatouille made easy in your pressure cooker or slow cooker. This post has been sponsored by Muir Glen. All thoughts and opinions are my own.

A beautiful bowl of ratatouille. How to make easy Instant Pot or crock pot Ratatouille. This traditional French ratatouille dish recipe is a beautiful vegetarian or vegan entree.

Every late summer through early autumn I make ratatouille at least once or twice. Eggplant is one of Yummy Hubby’s favorite foods, so when it’s in season I try to use it as much as possible for things like pasta, pizza, caponata, the Best Veggie Lasagna, or a healthy Vegan Eggplant Parmesan.

My favorite way to use seasonal produce is to keep it simple. A less is more approach that lets the ingredients stand out. Often I’ll simply slice and add summer squash, portobello mushrooms, peppers, tomatoes, and eggplant on the outdoor grill and top with some homemade pesto, chimichurri, or tahini sauce.

Ratatouille is a great example of simply preparing seasonal veggies. Though it’s typically made on the stovetop (I use my Dutch oven), using the Instant Pot or slow cooker to make ratatouille makes it easier than ever and keeps the kitchen cool. 

What is Ratatouille? 

Ratatouille is a traditional rustic French vegetable stew originating around Nice. Modern interpretations of ratatouille include beautifully swirled sliced vegetablesThis pressure cooker or slow cooker ratatouille is the traditionally simple rustic stew version. 

Ingredients for ratatouille coming out of a grocery bag.
 

Ratatouille Ingredients 

I picked up all the ingredients I needed at my local Vons grocery store. This is the store closest to my house. I love that I can easily find all the organic ingredients I need. I grabbed the produce in the organic section and the canned tomatoes and jarred olives in the canned vegetable section. There’s also a Vons mobile app where you can find coupons. 

Traditional ratatouille is made with just a few simple ingredients: 

  • Eggplant: 1 large diced eggplant. 
  • Zucchini (courgettes if you’re in Europe): sliced or diced.  
  • Peppers: diced. 
  • Tomatoes: I used Muir Glen Organic Diced Tomatoes in this recipe, which are grown in California and go from field to can in 8 hours or less.  
  • Onions: yellow onions are best here. 
  • Garlic: add more garlic at the end if the flavor disappears too much during cooking. 
  • Thyme: I love lots of fresh herbs, so I also add basil and/or parsley for garnish. 
  • Olive oil 

How to Make Pressure Cooker or Slow Cooker Ratatouille 

A wooden spoon stirs yellow onions in an Instant Pot on saute mode.

Saute the onions and garlic. 

Red bell peppers, eggplant, and onions in an Instant Pot to make ratatouille.

Layer the vegetables on top. 

The ingredients for rustic ratatouille are layered in an Instant Pot pressure cooker.

I start with eggplant on the bottom and end with zucchini. It’s important not to cut the zucchini too small, or it will become overcooked. 

A can of diced tomatoes gets poured into a crock pot or Instant Pot to make ratatouille.

Top the vegetables with Muir Glen organic diced tomatoes. When pressure cooking with tomatoes, it’s important to never stir the mixture before closing the lid and cooking, or the tomatoes will likely burn on the bottom. This is not a problem when slow cooking, however. Muir Glen Organic Diced Tomatoes are perfect for when you want to see beautifully diced tomatoes and have a clean, bright, sweet-tart flavor. 

A bowl of rustic ratatouille.

After cooking, there will be quite bit of liquid. Use a slotted spoon to transfer the ratatouille to a serving dish, and discard the extra liquid or save it for soup for another day.

Stir in the olives. If you find your ratatouille needs more flavor at this point, stir in another two cloves of crushed garlic and season with salt and pepper. I like crushed red pepper flakes to add heat in this recipe. I also find the flavor is much better a day after cooking. 

A bowl of ratatouille served with quinoa and fresh basil. The traditional rustic ratatouille can be made in the crock pot slow cooker or Instant Pot pressure cooker.

What to Serve with Ratatouille

Ratatouille is served as a side dish or as a main course with a piece of bread or polenta alongside. Here are some ideas for serving ratatouille as a main dish. 

  • With a chunk of good crusty sourdough bread. 
  • In a bowl with soft polenta. 
  • Topped with goat cheese or a creamy plant-based alternative. 
  • Alongside or on top of pasta drizzled with olive oil for a kid-friendly option. 
  • This ratatouille recipe is even tastier warmed up the next day. 
Yield: Serves 4

Pressure Cooker or Slow Cooker Ratatouille

Prep Time 10 minutes
Cook Time 2 minutes
Additional Time 20 minutes
Total Time 32 minutes

How to make easy pressure cooker or crock pot Ratatouille. This traditional French ratatouille dish recipe is a beautiful vegetarian or vegan entree.

Pressure Cooker or Slow Cooker Ratatouille

Ingredients

  • 2 tablespoons extra virgin olive oil, divided
  • 1 large yellow onion, diced
  • 5 cloves garlic, sliced
  • 1/3 cup water or white wine (for Instant Pot only)
  • 1 large eggplant, 1” dice
  • 1 red bell pepper, 1” dice
  • 3 zucchini, 1” dice
  • 4 sprigs fresh thyme
  • 1 bay leaf
  • 1 teaspoon sea salt
  • 1/4 teaspoon red pepper flakes
  • 2 (15 oz.) cans Muir Glen Organic Diced Tomatoes
  • 1 cup pitted olives (Nicoise, Kalamata, etc.)
  • 1 bunch fresh basil, for garnish

Instructions

Pressure Cooker

  1. Heat 1 tablespoon of the olive oil in the pressure cooker on saute mode. Add the onion and saute until translucent, about 3 minutes. Add the garlic and saute another minute or two longer.
  2. Add the water or wine to deglaze the pot, scraping up any bits that may be stuck to the bottom. Select cancel.
  3. Layer the eggplant, bell pepper, zucchini, thyme, bay leaf, salt and pepper. Top with the diced tomatoes and do not stir.
  4. Lock the lid, with valve set to sealing. Set to pressure cook for 2 minutes. The Instant Pot will take about 16 minutes to come up to pressure before. When pressure cooking ends, immediately carefully quick release the pressure. Carefully remove the lid and ensure the eggplant is tender. If not, replace the lid and pressure cook for 1 minute longer.
  5. Use a large slotted spoon to transfer the ratatouille to a serving dish. I like to use a casserole dish that can go into the oven or microwave for reheating. There will be quite a bit of liquid remaining in the pot, which you can discard or save and add to a soup another day.
  6. Stir in the olives. Season to taste with additional salt, pepper, and 1 clove minced garlic. Drizzle with the remaining olive oil. Serve warm. See serving suggestions in the notes below.

Slow Cooker

  1. Layer the vegetables and thyme in the slow cooker. Sprinkle with salt and pepper and drizzle with olive oil. Top with the diced tomatoes.
  2. Cook on low for 7 hours or high for 2-3 hours, just until the vegetables are tender.

Notes

How to serve:

  • With a chunk of good crusty sourdough bread. 
  • In a bowl with soft polenta. 
  • Topped with goat cheese or creamy plant based alternative. 
  • Alongside or on top of pasta drizzled with olive oil for a kid-friendly option. 
  • This ratatouille recipe is even tastier warmed up the next day. 

Nutrition Information:
Yield: 4 Serving Size: 1
Amount Per Serving: Calories: 252 Total Fat: 12g Saturated Fat: 2g Trans Fat: 0g Unsaturated Fat: 9g Cholesterol: 0mg Sodium: 843mg Carbohydrates: 31g Net Carbohydrates: 0g Fiber: 9g Sugar: 13g Sugar Alcohols: 0g Protein: 5g
Nutrition information is automatically calculated by Nutritionix. I am not a nutritionist and cannot guarantee accuracy. If your health depends on nutrition information, please calculate again with your favorite calculator.