Add all the cheese sauce ingredients except the water to a food processor or blender. Blend until smooth, adding water as needed to thin the sauce. Set aside.
Heat a large pan over medium heat and add frozen onions and peppers. Cook for 4-5 minutes to thaw.
Add pulled rotisserie chicken, black beans, and fire roasted corn to the pan. Cook for 2-3 minutes until heated through.
Remove from heat and stir in the cheese sauce until well combined.
Spoon about 8 oz of the cheesy chicken mixture onto each flour protein tortilla and roll tightly.
Heat a griddle or nonstick skillet over medium heat. Grill each burrito for 30-60 seconds per side until golden brown.
Serve warm and enjoy your cheesy rotisserie chicken burritos!