In a skillet, heat olive oil over medium heat. Add the diced red onion and sauté until translucent (about 3–4 minutes).
Stir in the diced red bell pepper and cook for another 3 minutes until slightly softened.
Add the cooked brown rice, black beans, corn, ground cumin, chili powder, garlic powder, salt, and pepper to the skillet. Stir everything together and cook for 5–7 minutes until heated through.
Remove the skillet from heat and set the mixture aside to cool slightly.
To assemble the burrito wraps, lay each tortilla flat on a clean surface.
Spoon a generous amount of the veggie mixture onto the center of each tortilla. Top with several slices of avocado.
Fold in the sides of the tortilla and roll it away from you to create a tight wrap. Repeat with the remaining tortillas and filling.
For extra flavor, you can grill the burritos in a hot, dry skillet for 1–2 minutes on each side until golden and slightly crispy.
Notes
Slice the burritos in half diagonally and garnish with chopped cilantro and lime wedges for serving.