ROASTED MONKFISH, FENNEL, AND CHESTNUT TAGINE

Steps:

• Preheat oven to 425°F.
• Cut 1 fennel bulb half lengthwise into paper-thin slices with a mandoline or other manual slicer and toss with oil and salt and pepper to taste. Cut remaining fennel lengthwise into 1/3-inch-thick sticks.
• Heat 3 tablespoons butter in a well-seasoned 10-inch cast-iron or heavy nonstick skillet over moderately high heat until foam subsides, then cook fennel sticks in 2 batches with salt and pepper to taste over moderate heat, stirring occasionally, until tender and edges are golden brown, about 7 minutes. Transfer to a bowl with a slotted spoon, reserving skillet, and keep warm, covered.
• Halve chestnuts and add to skillet with 1 tablespoon butter and salt and pepper to taste. Cook over moderate heat, stirring occasionally, until golden brown, about 3 minutes. Transfer to bowl with fennel using slotted spoon, reserving skillet, and keep warm, covered.
• Blanch fig leaves in boiling salted water 2 minutes, then transfer to a bowl of ice and cold water to stop cooking and drain well. Trim stems from leaves.
• Pat fish dry and season with salt and pepper. Add 1 tablespoon butter to skillet and heat over moderately high heat until foam subsides. Sear fish in 2 batches, turning once, until golden brown, about 2 minutes, transferring to a plate.
• Melt remaining tablespoon butter in skillet, then remove skillet from heat. If not using fig leaves, drizzle pieces of fish with butter. If using fig leaves, arrange 1 leaf, smooth side down, on a work surface, then put a piece of fish in middle and drizzle with some of melted butter. Wrap fig leaf around fish to enclose it and secure with wooden toothpicks. Wrap remaining fish in same manner.
• Boil 1/2 cup sauce in skillet until reduced to about 1/3 cup, about 2 minutes. Stir in chestnuts and cooked fennel and transfer to a wide shallow heavy pot (with a tight-fitting lid) just large enough to hold fish in 1 layer. Top chestnut mixture with fish. Cover pot with lid and roast in middle of oven until fish is just cooked through, 12 to 15 minutes.
• While fish is roasting, heat remaining 1/2 cup sauce in a small saucepan over moderate heat until hot.
• Remove toothpicks and open fig leaves. Serve fish (with fig leaves) over chestnut mixture and scatter with raw fennel. Serve warm sauce on the side.