Make swordfish shine with slow cooking, cucumber topping

Daniel J. van Ackere/America's Test Kitchen via APCucumber combines with mint, parsley, lemon and garlic to make both an insulating bed for swordfish steaks to cook en cocotte and a flavor-packed topping.

The premise behind the French method of cooking en cocotte (or casserole roasting) is to slow down the cooking process in order to concentrate flavor.

Fish cooked for an extended period of time usually winds up dry, but a combination of low oven temperature, moist-heat environment and the right cut of fish allows it to remain juicy and tender.

We found that meaty swordfish steaks were particularly well-suited to cooking en cocotte. The fresh Mediterranean flavors of mint, parsley, lemon and garlic easily combined with sliced cucumber to make an insulating layer on which to cook the fish; we then turned the cucumber mixture into a complementary, flavorful topping for serving.

It is important to choose steaks that are similar in size and thickness to ensure that each piece will cook at the same rate. If swordfish isn’t available, you can substitute halibut.


Start to finish: 1 hour

Servings: 4

3/4 cup fresh mint leaves

1/4 cup fresh parsley leaves

5 tablespoons extra-virgin olive oil

2 tablespoons lemon juice

4 garlic cloves, minced

1 teaspoon ground cumin

1/4 teaspoon cayenne pepper

Salt and pepper

3 shallots, sliced thin

1 cucumber, peeled, seeded and sliced thin

4 (4- to 6-ounce) skin-on swordfish steaks, 1-11/2 inches thick

Adjust an oven rack to the lowest position, and heat the oven to 250 degrees.

Process the mint, parsley, 3 tablespoons oil, lemon juice, garlic, cumin, cayenne and 1/4 teaspoon salt in a food processor until smooth, about 20 seconds, scraping down sides of bowl as needed.

Heat remaining 2 tablespoons oil in a Dutch oven over medium-low heat until shimmering. Add the shallots, cover and cook, stirring occasionally, until softened, about 5 minutes. Off heat, stir in the processed mint mixture and cucumber.

Pat the swordfish dry with paper towels, and season with salt and pepper. Place swordfish on top of cucumber-mint mixture. Place a large sheet of aluminum foil over pot, and press to seal, then cover tightly with lid. Transfer pot to oven, and cook until swordfish flakes apart when gently prodded with paring knife and registers 140 degrees, 35-40 minutes.

Carefully transfer swordfish to a serving platter. Season cucumber-mint mixture with salt and pepper to taste, then spoon over swordfish. Serve.

Nutrition information per serving: 382 calories; 237 calories from fat; 26 g fat (5 g saturated, 0 g trans fats); 84 mg cholesterol; 257 mg sodium; 9 g carbohydrate; 2 g fiber; 3 g sugar; 27 g protein.