Washington Post, simple recipe.
Ingredients
For the trout
4 (4 1/2- to 5-1/2 ounce) fresh trout fillets, or any other firm, white-fleshed fish, such as sea bass or tilapia
1/4 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
1 tablespoon extra-virgin olive oil
8 thin lemon slices from 1 large lemon
For the caper salsa
2 tablespoons extra-virgin olive oil
3 shallots (about 7 ounces total), thinly sliced
4 cloves garlic, thinly sliced
1/4 cup (1 3/4 ounces) drained capers
3 tablespoons unsalted butter
1 tablespoon fresh lemon juice
1 teaspoon grated lemon zest
1/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
Chopped fresh flat-leaf parsley leaves, for serving (optional)
Instructions
1. Make the trout: Position a rack in the center of the oven, and preheat to 325 degrees. Line a large, rimmed baking sheet with parchment paper. Place the fillets on the prepared baking sheet. Season the fish with salt and pepper, and drizzle it with the oil. Place two slices of the lemon on each fillet.
2. Roast the fish on the middle rack of the oven for 12 to 15 minutes, or until a thermometer inserted in the thickest part of the fish registers 130 degrees and the fish is flaky and separates easily with a fork. (Thicker fillets may need 2 to 3 more minutes.)
3. Make the salsa: While the fish is baking, place a saucepan over medium-high heat, then heat the oil until shimmering. Add the shallots and garlic and cook, stirring constantly until they soften, 2 to 3 minutes. Add the capers, stir and cook, stirring constantly, until the shallots just begin to darken, about 2 minutes. Add the butter and stir until melted. Remove from the heat, and stir in the lemon juice and zest. Season with the salt and pepper.
4. To serve, transfer the trout to a serving platter. Spoon the caper salsa on top, then sprinkle with the parsley, if using.