Prep the ingredients: Blend chipotle peppers in adobo sauce until smooth. Slice limes in half. Chop mango, cabbage, and cilantro, and crumble Cotija cheese.
Preheat the grill to medium-high heat.
Prepare the fish: Coat fillets with olive oil and season with sea salt.
Grill the limes cut-side down for about 3 minutes until slightly charred.
Make the sauce: In a small skillet (on the grill or stovetop), combine butter, blended chipotle peppers, raspberry preserves, and the juice from one grilled lime. Heat until warm and slightly bubbly (5–10 minutes), stirring occasionally.
Grill the fish: Cook until the flesh is opaque and flakes easily (about 5–6 minutes per side). Squeeze the juice from another grilled lime over the fish before removing it from the grill.
Warm the tortillas for about 1 minute per side on the grill.
Assemble the tacos: Layer cabbage, mango, grilled fish, and drizzle with raspberry chipotle sauce. Top with Cotija cheese and cilantro. Serve with extra lime wedges.