Tilapia with Chile Lime Butter

For chile lime butter 1/2 stick (1/4 cup) unsalted butter, softened                                          1 tablespoon finely chopped shallot 1 teaspoon finely grated fresh lime zest 2 teaspoons fresh lime juice 1 teaspoon minced fresh Thai or serrano chile (preferably red), including seeds 1/2 teaspoon salt

For fish 6 (5- to 6-oz) pieces skinless tilapia fillet or farm-raised striped bass fillets with skin 1/2 teaspoon salt 2 tablespoons vegetable oil Make chile lime butter: Stir together butter, shallot, zest, lime juice, chile, and salt in a bowl. Prepare fish: If using striped bass, score skin in 3 or 4 places with a thin sharp knife to prevent fish from curling (do not cut through flesh). Pat fish dry and sprinkle with salt. Heat 1 tablespoon oil in a 12-inch nonstick skillet over moderately high heat until just smoking, then saute 3 pieces of fish, turning over once with a spatula, until golden and just cooked through, 4 to 5 minutes, and transfer to a plate. Saute remaining fish in remaining tablespoon oil in same manner. Serve each piece of fish with a dollop of chile lime butter. Cooks' note: • Chile lime butter can be made 1 day ahead and chilled, covered. Bring to room temperature before using. Some people may want the dish to be even a bit more spicey and they may choose to increase the amount of chile or add pepper, chili pepper, etc. Makes 6 servings.