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Baked whole flounder with herb butter is a 30-minute dinner worth repeating

(Scott Suchman for The Washington Post/food styling by Lisa Cherkasky for The Washington Post)
Baked Flounder With Herb Butter
Active time:20 mins
Total time:30 mins
Servings:3 to 4
Active time:20 mins
Total time:30 mins
Servings:3 to 4
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Do you tend to overthink things? I know I do sometimes.

This simple recipe for baked flounder is the perfect example of how sometimes the easiest path is the answer.

If you’ve ever been intimidated by cooking whole fish, this recipe might just strip away any trepidation. In her upcoming cookbook, “How to Cook,” Darina Allen calls this method a “master” recipe because it can be applied to cooking a variety of whole flat fish, including the flounder I used here. (She recommends that you also try it with Dover sole, lemon sole, halibut, brill or turbot. You can leave the head on or remove it.)

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You place the fish on a sheet pan, add between 1/4-inch and 1/2-inch of water and bake it in a 350-degree oven for 20 to 30 minutes. The result is a moist, flaky fish that you can finish with a simple sauce. (To make it easier to remove the skin, Allen suggests using a sharp knife to cut through the skin around the edge of the fish where the fins meet the flesh.)

Cooking times and the amount of water needed will vary with the size of the fish, but the secret is a bit more water than you think you might need. That’s because if all of the water evaporates, the fish will stick to the pan, Allen notes. If there’s a bit too much water, you can easily lift the fish out of it or pour off excess, so it’s not an issue.

Scale and get a printer-friendly, desktop version of the recipe here.

While the fish was baking, I melted the butter in a microwave-safe bowl and stirred in herbs and garlic for a quick sauce, as Allen recommends. (Try her buttery sauce or substitute your favorite citrusy sauce, aioli, salsa or even a quick blender Hollandaise.)

The prolific author, who co-founded the Ballymaloe Cookery School in Ireland with her brother, has filled her latest cookbook with 100 recipes that she describes as essential. She writes that, at her cooking school, she often encounters people who do not know basic cooking techniques that are steppingstones to quickly putting supper on the table. Her goal in “How to Cook” was to share recipes that home cooks can adapt and turn to again and again.

The foolproof way to cook fish is also one of the simplest: Roast it whole.

This one hits that mark. I’ve made this fish four times using one large fish, served family-style, rather than the four smaller ones that Allen recommends in her recipe.

An example of that overthinking I was talking about earlier: Several people suggested that I might improve the method by adding herbs and seasoning to the water to flavor the fish while it was baking, so I tried that, but, frankly, it was not necessary. The herby sauce adds all of the flavor you need. The only change I made was to chop some briny capers to toss on top of the baked fish.

After you pour any excess water off the sheet pan, you can peel away the top layer of skin and spoon the sauce on top of the fish right there in the pan. Or, if you want a prettier presentation for company (or for yourself!), carefully transfer the fish to a serving platter and then sauce it and top it with herbs and capers there.

In the 20 minutes it took for the fish to bake, I easily made the sauce, tossed together a big green salad, chilled a bottle of sauvignon blanc and even set the table, candle and all. That makes this fish recipe a keeper.

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Scale and get a printer-friendly, desktop version of the recipe here.

Leftover fish can be refrigerated for up to 2 days.

NOTE: Ask your fishmonger to scale and gut the fish. This baking method allows you to cook it with the head on or removed.


  • 1 fresh whole flounder or other flat fish (about 2 1/2 pounds), gutted (see NOTE)
  • Water, as needed
  • 4 tablespoons (2 ounces) unsalted butter
  • Juice and finely grated zest from 1 lemon, plus optional lemon wedges for serving
  • 1 1/2 tablespoons finely chopped fresh flat-leaf parsley, oregano and/or thyme leaves (or your favorite herb combination; if substituting dried herbs generous 1 teaspoon total), plus optional herb leaves for serving
  • 2 cloves garlic, finely grated or minced
  • 1 teaspoon chopped capers, plus more as needed (optional)

Step 1

Position a rack in the middle of the oven and preheat to 350 degrees.

Rinse the fish and clean the slit by the head thoroughly. Lay the fish on a rimmed sheet pan. Using a sharp knife, cut through the skin around the edge of the fish where the fins meet the flesh. Do not cut deeply into the flesh. Be careful to cut neatly and to cross the side cuts at the tail or the skin will be difficult to remove later.

Step 2

Add a scant 1/2 inch of water to the pan. Bake for 20 minutes, depending on the size of the fish, checking it after 15 minutes. The water will evaporate as the fish cooks, but some should still be in the pan at the end. If the pan dries completely, the fish will stick to the pan, so add more water as needed.

To check whether the fish is cooked, lift the flesh from the bone close to the head where the flesh is thickest; it should lift off the bone easily and be opaque.

Step 3

A few minutes before the fish is ready, melt the butter in a microwave-safe bowl, using short 10-second bursts, or in a small saucepan over medium heat. Then stir in the lemon juice and zest; parsley, oregano and/or thyme; and garlic.

Step 4

Pick up the fish skin down near the tail and pull it off gently (the skin will tear but should come off in long pieces). Serve the fish from the sheet pan, pouring off any remaining water, or transfer it to a warmed, rimmed platter.

Spoon the herbed butter on top. Sprinkle the capers and more fresh herb leaves on top and serve with lemon wedges, if using.

Nutrition Information

Per serving, based on 4 (about 6 ounces of fish and a scant 2 tablespoons of sauce)

Calories: 303; Total Fat: 17 g; Saturated Fat: 8 g; Cholesterol: 158 mg; Sodium: 914 mg; Carbohydrates: 1 g; Dietary Fiber: 0 g; Sugar: 0 g; Protein: 35 g

This analysis is an estimate based on available ingredients and this preparation. It should not substitute for a dietitian’s or nutritionist’s advice.

Correction: An earlier version of this recipe listed the wrong publisher for “How to Cook.” This has been corrected.

Adapted from “How to Cook” by Darina Allen (Kyle Books, 2021).

Tested by Ann Maloney; email questions to

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