Preheat The Oven: Start by preheating your oven to 350°F (175°C).
Prepare The Filling: In a large mixing bowl, combine the shredded chicken, diced onions, diced bell peppers, 1 cup of shredded cheddar cheese, chili powder, cumin, salt, and pepper. Mix until all the ingredients are well combined.
Assemble The Enchiladas: Take each flour tortilla and spoon a generous portion of the chicken and vegetable mixture onto the center. Roll up the tortilla tightly, tucking in the sides as you go, and place it seam-side down in a greased baking dish.
Make The Sour Cream Sauce: In a separate bowl, whisk together the sour cream and red enchilada sauce until well combined.
Pour Over The Enchiladas: Pour the sour cream and enchilada sauce mixture evenly over the rolled enchiladas in the baking dish. Make sure they are well coated with the sauce.
Add Cheese: Sprinkle the remaining 1 cup of shredded cheddar cheese over the top of the enchiladas.
Bake: Place the baking dish in the preheated oven and bake for approximately 25-30 minutes or until the enchiladas are heated through, and the cheese is melted and bubbly.
Garnish And Serve: Remove the enchiladas from the oven, garnish with chopped cilantro if desired, and serve hot.