Pan-Seared 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
1/2 teaspoon salt2 tablespoons vegetable oil


Make chile lime butter:
Stir together butter, shallot, zest, lime juice, chile, and salt in a bowl.


Prepare fish:
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 sauté 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. Sauté 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.