Grilled Fish Fillets with Black Peppercorn Crust

1/3 cup lemon juice
1/2 cup red wine vinegar
3 cloves garlic, crushed
1 1/2 tablespoons sugar
1/4 teaspoon salt
1 1/2 pounds firm white fish fillets
3 tablespoons cracked black peppercorns
3/4 cup stock
2 teaspoons chopped fresh thyme
2 tablespoons cold butter, cut into small pieces
thyme sprigs for garnish

Combine lemon juice, vinegar, garlic, sugar and salt. Place in a shallow dish and add fillets in one layer. Marinate 2 hours, turning once.

Preheat grill and spray with cooking spray.

Remove fillets from marinade and pat dry. Sprinkle half of cracked pepper over fillets and press into flesh. Turn fillets over and repeat.

Grill about 12 minutes, turning once. Meanwhile, strain marinade into a small saucepan and add stock and thyme. cook over medium heat until it is reduced to about 1/2 cup (about 5 minutes). Add butter, one piece at a time, whisking each piece until it is comepletely incorporated before adding another piece.

Pour sauce over fillets and garnish with thyme sprigs.
from Fish on the Grill.