- 1/2 cup (1 stick) butter, room temperature
- 1 tablespoon fresh lemon juice
- 1 tablespoon chopped fresh thyme
- 1 tablespoon chopped fresh chives
- 2 teaspoons grated lemon peel
- 4 very large Swiss chard leaves, halved lengthwise, center stems cut out
- 4 1-inch-thick halibut fillets (each 6 to 8 ounces)
Preheat oven to 450°F. Blend butter, fresh lemon juice, chopped fresh thyme, chopped fresh chives, and grated lemon peel in small bowl; season butter to taste with salt and pepper.
Place four 12-inch squares of foil on work surface. Overlap center edge of 2 chard halves on each square. Sprinkle fillets on each side with salt and pepper, then spread with some lemon-thyme butter. Top each with lemon slice. Place 1 fillet crosswise on widest part of chard. Fold bottom of leaf over fillet, then continue to roll up (sides will be open). Enclose each wrapped fillet in foil.
Arrange packets on rimmed baking sheet. Bake until fish is just opaque in center, 12 to 14 minutes. Transfer packets to plates, open foil, and serve.