Preheat the oven to 150°F. Start by splitting the salt, oil, and lime juice in half.
In a small bowl, mix chili powder, Mexican spice mix, paprika, garlic powder, cayenne, cumin, 1/4 tsp salt, and 3/4 tbsp oil. Marinate the fish with this mixture for 5 minutes.
Meanwhile, in another bowl, mix avocado, mango, red onion, and 1 tsp lime juice to make the salsa.
In a pan over medium heat, use the remaining 3/4 tbsp oil to sear the fish for 8 minutes until it’s brown. Remove the fish from the pan and discard the skin.
To make the sauce, mix sour cream, lime zest, remaining 1 tsp lime juice, and remaining 1/4 tsp salt in a bowl until well combined and smooth.
Bake tortillas for 5 minutes.
To assemble, shred the salmon and add the pieces onto the tortillas together with the salsa, jalapeno, and coriander. Pour the sauce on top.