Make this French summertime classic, Cod with Ratatouille. Eggplant, zucchini, tomatoes, bell pepper, and garlic make a rich and savory base for flaky panfried cod. The easy lemon butter sauce gives this dish a sophisticated finish.

panfried cod with ratatouille on a white tablecloth with flowers

I make ratatouille at least once every summer. Sometimes with grilled chicken, occasionally with pork chops but most often with panfried cod. Along with vinegar and spice baby back ribs and Thai-style flank steak salad is my tried and true summer dinner I come back to time and time again.

The magic of this recipe is its simplicity. A medley of colorful vegetables, simmered to perfection as ratatouille, forms the vibrant base for this dish. While the ratatouille cooks, flaky cod fillets are pan-seared to golden perfection. A luscious lemon butter sauce, bursting with bright, citrusy notes, brings it all together.

This cod with ratatouille and lemon butter sauce is perfect for everything from weeknight dinners to easy entertaining. Whether you enjoy it for a family feast, date night, or just Tuesday night, it’s going to be your summer jam, I just know it.

Cod with Ratatouille Recipe Highlights

Cod with ratatouille on a white plate with a fork on the plate.

This healthy recipe will be an instant summer classic for your kitchen. You’ll be obsessed! It’s…

PERFECTLY TENDER & FLAKY. Pan-searing or pan-frying white fish is a simple and quick way to cook fish fillets. Read my post on how to perfectly pan-sear fish for more details.

AN EXCELLENT DINNER PARTY RECIPE. If you like to host dinner parties but feel like you’re always making the same things. This is a crowd-pleasing dish that is a little more special than the everyday but not too difficult to make.

A VERSATILE CLASSIC. Once you learn the basics of ratatouille you will be making this classic French recipe on repeat all summer long. It highlights everything we love about summer; eggplant, ripe tomatoes, summer squash, and sweet bell peppers. This recipe has a couple of shortcuts that make it much easier too.

A classic, comforting dish with a few special touches! 💜 Read on to learn more about how to make cod with ratatouille.

Ingredients

Cod. I like to use Pacific cod for this recipe but any flaky white fish will work. Try halibut, sea bass, or sole
Lemon. You will need 2-3 lemons. One for marinating the fish and two for the lemon butter sauce.
Olive oil and butter. Olive oil is used to make the ratatouille and pan frying the fish and butter for the butter sauce.
Kosher salt and freshly ground black pepper. Essential to bring out all the flavors.
Tomatoes. Ripe garden plum tomatoes are wonderful here. You can also substitute the same amount of cherry tomatoes, be sure to cut those in half.
Eggplant. The eggplant makes the ratatouille rich and satiny. I’ve used all types of eggplant with great success. When testing the recipe I used the common globe eggplant but Japanese, Italian, or Chinese varieties would work just as well.
Yellow onion and garlic. A large onion and a few cloves garlic add body to the ratatouille and some nice sweetness. You could substitute red onion or shallots for additional sweetness.
Bell pepper. I used red bell pepper but yellow pepper or orange bell peppers would be great as well.
Zucchini or yellow squash. The last ingredient in the parade of summer vegetables that are featured in ratatouille. Use the traditional varieties or branch out with patty pan squash or other summer squash varieties.
Herbs. Bay leaves, Italian parsley, and rosemary are a flavorful combination but other options would be fresh basil leaves or sprigs of fresh thyme.

What Is Ratatouille?

A copper dish of ratatouille with a couple of fillets of cod on top with lemon slices

Aside from being the name of a very famous rat, ratatouille is a French dish made of Mediterranean summer vegetables from the region of Nice. Most French people (including Larousse Gastronomique) would tell you that you need to use separate pots for the vegetables and then cook them together at the end.

One of my favorite cookbooks, Le Creuset by Sheri Castle however, states that, “all-together recipes have their place as well.” In our recipe we do a little bit of both.

The eggplant gets fried on its own first until it is soft and succulent then removed from the pan. Next the onions get their turn to caramelize by themselves before the other ingredients get added to the same pan.

Making the ratatouille this way only uses one pan (not six like some cookbooks recommend) but still allows the slower cooking vegetables to have a bit more time to caramelize and bring out their unique flavors.

How To Make Cod with Ratatouille

step one

Prep the cod. Season the cod on both sides with salt and pepper then layer with lemon slices. Cover and refrigerate until ready to cook. The lemon doesn’t “marinate” it exactly but adds a little lemony touch.

Raw cod fillets in a dish with slices of lemon on top.

step two

Prep the ratatouille veggies. Cut all the vegetables for the ratatouille and set aside.

Glass bowls of chopped eggplant, zucchini, tomatoes, and more.

step three

Fry the eggplant. Heat 1/4 cup of olive oil in a large deep frying pan over medium heat. Add eggplant and toss to coat in the oil. Season with salt and pepper and fry, stirring frequently until the eggplant is soft and succulent, about 10-15 minutes. Remove from the pan.

A bowl of fried eggplant sitting on a wood counter.

step four

Finish the ratatouille. Return the pan to medium-high, add a little olive oil and the onions. Season again with a pinch of salt and pepper and sauté until translucent and starring to brown. Add the garlic and red pepper and saute a bit longer until the garlic is fragrant, about 3-4 minutes.

Add the zucchini, season again and continue cooking until the zucchini starts to become golden brown in places. Finally add the chopped tomatoes, eggplant, rosemary, and bay leaf and turn the heat to low. Simmer until the vegetables are tender but not mushy. Taste and add more salt if needed. Stir in the chopped parsley.

Zucchini and peppers being sautéed in a frying pan with a wood spoon.

step five

Make the butter sauce. While the ratatouille is cooking, make the lemon butter sauce by combining the butter, lemon juice, lemon zest, and all the other ingredients in a small saucepan and whisking over low heat until combined. Cover and keep warm.

A small saucepan of lemon butter sauce simmering

step six

Panfry the fish. Heat a couple tablespoons of oil in a large skillet over medium-high heat. Remove the lemon slices and add the fish pieces to the oil. Let cook, undisturbed until a nice golden crust has formed, about 1-2 minutes depending on the thickness of the fish fillet. Flip and cook a minute more on the other side. The fish is done when it easily flakes when pressed.

Fish pan frying in a pan with parsley on top.

step seven

Serve. Spoon some ratatouille onto each plate, top with a piece of fish and drizzle the butter sauce over everything. Serve with a lovely white wine and some crusty bread or my crockpot brown rice if you want something more substantial.

A copper dish full of Ratatouille with pieces of cod on top.

Easy Recipe Variations

This fish recipe is wonderful as it is, but if you want to add a few twists, feel free! A few ideas to get you started…

Switch up the butter sauce by simply whisking in some minced garlic, a touch of white wine, or browning the butter first. Get my tips on browning butter here.
Make it spicy! Add 1/2 teaspoon (or more) red pepper flakes to the ratatouille for some heat. Or drizzle some chili oil over the top of each dish.
Pan-fry other types of fish. While we are big fans of cod (you must make this lemon-broiled cod recipe), try using a different type of fish, thin fillets of delicate sole are lovely, or even shrimp would be delicious with the ratatouille.