Gremolata Butter Baked Cod

published Oct 15, 2022
Gremolata Butter Baked Cod Recipe

This parchment pouch fish and potato dinner is one you can easily make ahead.


Prep40 minutes

Cook16 minutes to 20 minutes

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Filet of cod that's been baked with butter, herbs, potatoes. on parchment on a plate. Fork has cut out a bite
Credit: Photo: Julia Gartland; Food Styling: Jessie YuChen

When it comes to cooking fish, few techniques are as foolproof as cooking en papillote, French for “in paper” (aka parchment paper). This variation of steaming isn’t exclusive to French cooking — many cultures use this technique with a variety materials like banana leaves, corn husks, or aluminum foil.

No matter the material, the concept remains the same: Ingredients are enclosed in an airtight package and cook together in the steam produced by their own juices. This not only infuses the fish with the other ingredient’s flavors, but it also helps maintain its moisture. Long story short: It’s much harder to overcook fish using this method.

I also love cooking en papillote to avoid the cleanup needed when pan-frying seafood. Wrapped up in a neat package, it’s possible even your baking sheet will remain spotless after making this dish. To serve, simply transfer each package to plates and let your guests cut open the puffy parchment to release a cloud of aromatic steam. It’s dinner and a show!

Credit: Photo: Julia Gartland; Food Styling: Jessie YuChen

What’s So Great About This Butter Baked Cod?

This simple cod en papillote is flavored with a variation on the classic Italian sauce gremolata. Instead of extra-virgin olive oil, softened butter is the base for the herby, garlicky sauce, which melts into the fish and vegetables as they cook. The fish sits atop thinly sliced potatoes and shallots, but most hearty veggies with fare well with this preparation. (Just be sure to slice them thinly.) No matter which you choose, be sure to have some crusty bread on hand. You don’t want to miss the buttery juices at the bottom of the packet.

What Type of Cod Is Best for Butter Baked Cod?

Wondering what type of cod to look out for at the grocery store? Check out Monterey Bay Aquarium’s Seafood Watch list for recommendations. Their recommendations change periodically, but in general Pacific cod from Alaska is a good bet.

Gremolata Butter Baked Cod Recipe

This parchment pouch fish and potato dinner is one you can easily make ahead.

Prep time 40 minutes

Cook time 16 minutes to 20 minutes

Serves 4

Nutritional Info


  • 4 tablespoons

    (1/2 stick) unsalted butter

  • 4

    (about 1-inch thick, 6-ounce) skinless cod fillets, thawed if frozen

  • 1 3/4 teaspoons

    kosher salt, divided

  • 1/2 teaspoon

    freshly ground black pepper

  • 12 ounces

    small Yukon Gold or red potatoes (1 1/2 to 2 inches wide, about 6)

  • 2

    medium shallots

  • 1/2 cup

    pitted kalamata olives (optional)

  • 1 tablespoon

    olive oil

  • 3 cloves


  • 10 sprigs

    fresh parsley, plus more for serving

  • 1

    medium lemon


  1. Place 4 tablespoons unsalted butter in a small bowl and let sit at room temperature until softened.

  2. Arrange 2 racks to divide the oven into thirds and heat the oven to 400ºF. Cut 4 (13x16-inch) sheets of parchment paper. Fold each parchment sheet in half crosswise so that the short sides are touching, then unfold and lay flat again.

  3. Pat 4 skinless cod filets dry with a paper towel. Season all over with 1 teaspoon of the kosher salt and 1/2 teaspoon black pepper. Place on a large plate and refrigerate.

  4. Prepare the following, adding each to a medium bowl as it is completed: Very thin slice 12 ounces small Yukon Gold or red potatoes and 2 medium shallots (about 1/8-inch thick). Halve 1/2 cup pitted kalamata olives. Add 1 tablespoon olive oil and 1/4 teaspoon of the kosher salt, and toss to combine.

  5. Prepare the following, adding each to the bowl of butter as it is completed: Mince 3 garlic cloves. Finely grate the zest of 1 medium lemon (about 1 tablespoon). Pick the leaves from 10 fresh parsley sprigs until you have about 1/2 cup, then finely chop (chop more parsley for garnish if desired). Add the remaining 1/2 teaspoon kosher salt and mix until combined.

  6. Assemble the parchment pouches: Divide the potato mixture between the 4 sheets of parchment, arranging it evenly on the center of one half of each sheet and leaving a 1-inch border. Top each portion with 1 piece of cod; if it is thinner on one side, tuck the thinner end under itself so that the fish is about an even thickness. Divide the butter mixture over the cod and use the back of a spoon to spread it into an even layer.

  7. Fold the other half of the parchment paper over the fish, then fold each open end over multiple times to completely seal the packet. Place the packets on 2 rimmed baking sheets.

  8. Bake for 10 minutes. Rotate the baking sheets between racks and continue to bake until the packets puff and the edges of the parchment begin to turn golden-brown, 8 to 10 minutes more. The potatoes should be tender and the cod should flake easily with little pressure. Meanwhile, cut the zested lemon into wedges.

  9. Place a parchment packet on each plate. Use caution when opening the packets, as they are quite steamy. Garnish with more chopped parsley if desired and serve with the lemon wedges.

Recipe Notes

Make ahead: The butter mixture can be made and refrigerated in an airtight container up to 1 day ahead. Let sit at room temperature until softened before using. Alternatively, the packets can be assembled up to 24 hours in advance and refrigerated before baking.

Parchment paper substitute: You can use aluminum foil instead of parchment, but you’ll lose the puffing/browning of the parchment paper, which are nice visual cues for doneness.

Storage: Leftovers can be refrigerated in an airtight container for up to 2 days.