In a medium bowl, stir together tomatoes, mango, yogurt, cilantro, chili sauce, and ½ teaspoon salt. Set aside
Place fish on foil-lined sheet. Drizzle with olive oil, sprinkle with salt, and squeeze lime juice over top. Broil 2–3 min until lightly charred and semi-firm. Remove and set aside
Warm tortillas in a nonstick skillet over medium-high heat
Remove skin from fish and divide fish among tortillas. Squeeze with remaining half lime, top with yogurt-mango mixture and lettuce, and serve
