For this dish, onions are caramelized in a hot oven with paper-thin strips of orange zest. Fresh or dried thyme provides a nice flavor accent.
2tablespoonsfresh orange juice
1teaspoon grated orange zest
1garlic clove, crushed
1teaspoonfresh thyme leaves or ¼teaspoondried thyme
2halibut steaks, or cod, salmon, or swordfish steaks, 1inch thick (about 1¼pounds)
Freshly ground black pepper
Combine the orange juice, grated zest, garlic, and thyme in a shallow dish. Add the fish and turn to coat, spreading the marinade over the surface. Sprinkle with pepper and let stand until ready to bake.
Heat the oven to 425°F.
Combine the oil, onion, slivered zest, and thyme in a 13 × 9-inch baking dish and stir to blend. Bake until the onions begin to brown, 20 minutes, stirring once after 10 minutes. Remove from the oven and add salt and a grinding of black pepper. Push the onions to the side of the dish and place the fish steaks in the center. Top with any marinade left in the dish. Spoon some of the onions over the fish. Bake until the center of the fish has turned from translucent to opaque, about 10 minutes. Remove from oven. Let stand 5 minutes before serving.
To serve, spoon the onion mixture onto a serving platter. Carefully remove the skin and center bone from the fish. Transfer the fish to the platter. Top each portion with a spoonful of onion and a small sprig of thyme, if using.