Season the chicken with chili powder, paprika, cumin, garlic powder, salt, and pepper, then set it aside. Warm each tortilla in a dry skillet for a few seconds on each side until soft, then set aside. Heat avocado oil in the same skillet over medium heat and cook the chicken until golden and fully cooked. Let the chicken rest for a couple of minutes, then dice it into small pieces.
In a small bowl, mix Mexican crema, chipotle peppers, and lime juice, adjusting the spice and tanginess to your liking.
Using the same skillet, add more avocado oil if needed. If you're using onions, cook the sliced red onions first until softened. Then stir in the black beans and corn, heating everything through.
Lay a warmed tortilla flat. Add rice to the center, followed by the black beans and corn mixture, diced chicken, a drizzle of chipotle crema, and shredded lettuce. Add avocado slices if desired. Fold the sides inward, roll tightly from the bottom, and toast in a dry skillet seam-side down for 1 minute per side.
Slice in half, garnish with fresh cilantro and lime wedges if you like, and enjoy!