In a large skillet, heat 2 tablespoons of olive oil over medium-high heat.
Add 1 to 1.25 pounds of diced boneless skinless chicken breast to the heated oil. Cook for about 5 minutes, stirring occasionally, until the chicken is browned and cooked through.
Sprinkle the 1.25-ounce packet of taco seasoning over the chicken. Stir well to coat the chicken evenly.
Add the diced red bell pepper, drained and rinsed black beans, and frozen corn. Mix everything together and cook for an additional 3-4 minutes until the vegetables are tender.
Pour in the 8-ounce can of tomato sauce and stir well to combine. Let the mixture simmer for 1-2 minutes until heated through.
Sprinkle 1 to 2 cups of shredded Mexican cheese blend over the top of the skillet. Cover with a lid and allow the cheese to melt for about 2 minutes.
Once the cheese is melted, remove the skillet from heat. Garnish with diced green onions and fresh cilantro. Serve hot with optional sides of Spanish rice, tortilla chips, or tortillas.
