Preheat grill to 375 degrees. Grill corn until it starts to brown and char. Remove corn from grill. (Alternately, you can put corn into a pot of water, cover the pot, bring to a boil and then turn off the heat. Corn can remain in the pot of boiled water until ready to serve). Cut kernels off the ears of corn.
Peel skin off avocados and remove pits. Place into a small bowl and smash with a fork. Season with salt and pepper.
Make the crema: Whisk sour cream, mayo, chili pepper and lime juice together in a small bowl and set aside.
Make the slaw: Shred the cabbage. In a bowl, whisk all of the ingredients together. Fold in the slaw until coated. Refrigerate until ready to serve.
Heat vegetable oil in a large frying pan over medium heat. Combine flour, salt and pepper and whisk together. Toss cubed fish into the flour mixture. Remove fish from flour mixture with a slotted spoon to shake off any excess flour and place into the pan in an even layer.
Allow fish to cook 4-5 minutes until browned, then flip. Continue to brown and flip until fish is well-browned on all sides and a crust begins to form. (Feel free to add more oil during cooking if needed.) Sprinkle cheese evenly over the fish and cover the pan. Remove from heat.
Warm the tortillas in the microwave for 20-30 seconds. Keep covered with a dish towel until ready to serve.
Lay warm tortillas on a flat surface. Smear a dollop of avocado down the center of each tortilla. Lay pan-fried fish on top of the avocado, down the center. Garnish with slaw, corn and a drizzle of chili crema.