Preheat the oven to 375ºF and grease the pan with avocado oil.
Add the chicken strips, salsa, fajita seasoning, and salt to a bowl and toss until the chicken is coated in spices and salsa. Let the chicken marinate for at least 10 minutes (longer for extra flavor).
Transfer the peppers, onions, and garlic to the baking sheet and drizzle the avocado oil over the vegetables and season them with fajita seasoning. Toss all of the ingredients together until the veggies are coated. Spread the vegetables out over half of the baking sheet.
Spread the chicken strips out over the other half of the baking sheet. Bake everything together for 30 minutes, tossing halfway through the cooking time.
While the chicken and veggies are cooking, prepare the rice. Rinse the rice under cold water and then transfer the rice to a medium-sized saucepan. Add 1.5 cups of water, avocado oil, and salt to the rice and bring to a boil over medium/high heat. Turn the heat to low and cover. Simmer the rice for 15-20 minutes or until the rice has a bit to it and is not mushy. Remove the rice from the heat and fluff with a fork.
Add the black beans to the rice and stir to combine. Set aside.
For the chicken and veggies, turn the heat to broil after 30 minutes and broil the chicken and peppers for 2-4 minutes until the chicken and peppers brown and form crispy edges.
Remove from the oven and let the chicken and veggies rest for 10 minutes before building the burritos.
Lay the tortillas out on a flat surface and add about ¼ cup of the rice and bean mixture to the middle of each tortilla. Then, add about ¼ cup of chicken and ¼ cup of veggies over the top of the rice and beans. Top each burrito off with 1 tablespoon of cotija crumbles.
Tightly wrap each burrito by folding the sides in and rolling.
If you are going to eat the chicken burritos right away, feel free to eat the burrito as is, freeze the burritos or heat the burritos up in the oven or on the stop top.