1. Heat a large skillet over medium heat. Add cumin seeds; cook 2 minutes or until toasted, shaking pan frequently. Place cumin, 1/2 teaspoon salt, paprika, and black pepper in a spice grinder; process until finely ground. Combine cumin mixture and garlic; rub over fish. Return the skillet to medium-high heat. Add oil to pan; swirl to coat. Add fish; cook 2 minutes on each side or until done. Remove from heat; keep warm.
2. Combine the remaining 1/4 teaspoon salt, avocado, and next 6 ingredients (through 1/4 teaspoon red pepper). Stir in jalapeño, if desired.
3. Heat tortillas according to package instructions. Break fish into pieces; divide evenly among tortillas. Top each tortilla with 2 tablespoons salsa. Fold tortillas in half; serve immediately.