Mushroom-Crusted Flounder with Creamy Spinach

Method

1. Preheat the broiler and position a rack 8 inches from the heat. In a large skillet, melt 1 tablespoon of the butter over moderately high heat. Add 1 garlic clove and half of the chopped shallot and cook until fragrant, about 1 minute. Add the baby spinach and cook, tossing, until wilted.
2. Pour in the heavy cream and cook over moderately high heat, stirring occasionally, until thickened, about 7 minutes. Stir in the pinch of cayenne, then season with salt and pepper to taste. Keep the creamed spinach warm over low heat.
3. Meanwhile, in a medium skillet, melt another 1 tablespoon of the butter over moderate heat. Add the remaining garlic clove and the remaining chopped shallot and cook, stirring, until fragrant, about 2 minutes. Add the sliced shiitake mushrooms, season with salt and pepper, and cook, stirring occasionally, until tender, about 4 minutes.
4. Remove the mushroom mixture from the heat. Stir in the remaining 2 tablespoons of butter and the bread crumbs until combined. Set aside.
5. Lightly brush a large baking sheet with vegetable oil. Arrange the flounder fillets on the sheet in a single layer. Evenly divide and pat the mushroom mixture onto the top of each fillet, pressing gently.
6. Broil the fish 8 inches from the heat for 4 to 5 minutes, until cooked through and the topping is lightly browned. Transfer the fillets to plates, spoon the creamed spinach alongside, sprinkle with chopped parsley, and serve immediately.