Why This Recipe Works

For a foil-baked fish recipe with flaky fish and tender but firm vegetables flavored by the aromatic goodness of their mingled juices, we chose mild haddock or cod over more assertive salmon or tuna, which can overpower vegetables. Placing the packets on the lower-middle rack of the oven close to the heat source concentrated the exuded liquid and deepened its flavor. Vegetable selection was important (potatoes failed to cook evenly in the packets, and eggplant turned to mush), as was preparation (carrots and leeks could be added raw but fennel had to be wilted slightly in the microwave). Adding a final flavoring touch—a tomato and olive oil “salsa” or a compound butter—contributed to a full-flavored sauce that perfectly complemented the fish.

Before You Begin

Haddock, red snapper, halibut, and sea bass also work well in this recipe and those that follow as long as the fillets are 1 to 1¼ inches thick. The packets may be assembled several hours ahead of time and refrigerated until ready to cook. If the packets have been refrigerated for more than 30 minutes, increase the cooking time by 2 minutes. Open each packet promptly after baking to prevent overcooking. Zest the lemon before cutting it into wedges. See illustrations below for tips on cutting the carrots and leeks.

Instructions

Combine butter, ¼ teaspoon zest, 1 teaspoon garlic, thyme, ¼ teaspoon salt, and 1/8 teaspoon pepper in small bowl. Combine parsley, remaining teaspoon zest, and remaining teaspoon garlic in another small bowl; set aside. Place carrots and leeks in medium bowl, season with salt and pepper, and toss together.

Adjust oven rack to lower-middle position and heat oven to 450 degrees. Cut eight 12-inch sheets of foil; arrange four flat on counter. Divide carrot and leek mixture among foil sheets, mounding in center of each. Pour 1 tablespoon vermouth over each mound of vegetables. Pat fish dry with paper towels; season with salt and pepper and place one fillet on top of each vegetable mound. Spread quarter of butter mixture on top of each fillet. Place second square of foil on top of fish; crimp edges together in ½-inch fold, then fold over three more times to create a packet about 7 inches square (see illustrations, above). Place packets on rimmed baking sheet (overlapping slightly if necessary).

Bake packets 15 minutes. Carefully open foil, allowing steam to escape away from you. Using thin metal spatula, gently slide fish and vegetables onto plate with any accumulated juices; sprinkle with parsley mixture. Serve immediately, passing lemon wedges separately.