1. Combine pineapple, chopped red onion, jalapeño, cilantro, 1 tablespoon lime juice, and 1/4 teaspoon salt in a small bowl.
2. Combine remaining 2 tablespoons lime juice, sliced red onion, basil, tomato, avocado, and 1 tablespoon oil in a bowl; sprinkle with 1/4 teaspoon salt.
3. Heat a large nonstick skillet over medium-high heat. Add remaining 1 tablespoon oil to pan; swirl to coat. Sprinkle fish with remaining 1/4 teaspoon salt, cumin, and chipotle chile powder. Add fish to pan; cook 3 minutes on each side or until fish flakes easily when tested with a fork. Spoon pineapple salsa over fish. Serve with tomato and avocado salad.