Using a serrated bread knife, cut rolls in half horizontally. Discard top halves of rolls, or save for another use. Spread butter onto cut surface of rolls. Place buttered rolls on prepared baking sheet, butter side up.
Bake until light golden brown, 5 to 7 minutes.
In a medium sauté pan, heat ½ teaspoon olive oil over medium-high heat.
Drizzle remaining ½ teaspoon olive oil, and sprinkle salt, garlic powder, pepper, and paprika on both sides of fillets.
Cook fillets until seared, opaque, and easily flaked, 2 to 3 minutes per side. Keep warm.
Top each toasted roll with a lettuce leaf, trimming to fit.
Cut fillets into 8 pieces to fit rolls, and place a piece on each. Top fillets with Mango Salsa.
Serve immediately.
Recipe by TeaTime Magazine at https://teatimemagazine.com/mango-salsa-mahi-mahi-canapes/