Catfish with Green Olives

1 cup pimiento-stuffed green olives, drained, rinsed, and chopped
2 tablespoons extra-virgin olive oil
1 teaspoon finely grated fresh lemon zest
3 tablespoons chopped fresh flat-leaf parsley
4 (6-oz) catfish fillets
Accompaniment: lemon wedges

Stir together olives, oil, zest, and 2 tablespoons parsley in a bowl.

Arrange catfish, skinned sides down, in an oiled 12-inch nonstick skillet, tucking thinner ends of each fillet under. Season fish with salt and pepper, then mound olive mixture on top. Put a round of parchment or wax paper on top of olive mixture, then tightly cover skillet.

Cook catfish over moderate heat until just cooked through, 8 to 10 minutes. S

Serve sprinkled with remaining tablespoon parsley.