2/3 cup plain fat-free yogurt |
1/2 cup chopped seeded cucumber |
1/4 teaspoon dried mint, crushed |
1/4 cup finely chopped red onion |
1/8 teaspoon salt |
1/8 teaspoon freshly ground black pepper |
4 (6-ounce) grouper fillets or other firm white fish fillets (about 1 inch thick) |
cooking spray |
1 (1-ounce) slice white bread |
1 tablespoon butter, melted |