1/2 cup reduced-fat sour cream |
1 jalapeno pepper, seeded and finely chopped |
1 tablespoon fresh lime juice (1/2 lime) |
1/4 cup chopped fresh cilantro |
1/4 teaspoon salt |
1 tablespoon chili powder |
1/4 teaspoon salt |
4 (6 ounce) tuna steaks (about 1 inch thick) |
cooking spray |