In a medium bowl, combine the chili powder, ground cumin, smoked paprika, garlic powder, onion powder, salt, and black pepper.
Add the thinly sliced chicken breast to the bowl and toss to coat evenly with the spice mixture.
Heat the olive oil in a large skillet over medium-high heat.
Add the seasoned chicken slices to the skillet and cook for 5-7 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced red bell pepper, green bell pepper, and yellow onion.
Sauté the vegetables for 6-8 minutes until they are tender and slightly caramelized.
Return the cooked chicken to the skillet with the vegetables and stir to combine. Cook for an additional 1-2 minutes to heat through.
Warm the whole wheat tortillas in a dry skillet or microwave for 20 seconds to make them pliable.
To assemble each burrito, lay a tortilla flat and spread 1/4 cup of cooked brown rice in the center.
Add 1/4 cup of cooked black beans on top of the rice.
Spoon a generous portion of the chicken and vegetable mixture over the beans.
Sprinkle 2 tablespoons of shredded cheddar cheese and a tablespoon of chopped cilantro over the filling.
Add 2 tablespoons of plain Greek yogurt on top.
Fold the sides of the tortilla over the filling, then roll from the bottom up to form a burrito.
Repeat with the remaining tortillas and filling.
Serve the burritos warm with extra Greek yogurt or salsa if desired.