1/3 cup chopped fresh basil
1 tablespoon olive oil
2 large tomatoes, seeded and finely chopped
1 Serrano pepper, seeded and minced
1/4 cup finely chopped red onion
2 tablespoons chopped fresh cilantro
1 tablespoon fresh lime juice
1/2 teaspoon salt
2 (4-ounce) skin on salmon fillets
1/8 teaspoon freshly ground black pepper