This is the breakfast of cowboys: hearty and complete. Slideshow: More Mexican Recipes
Preheat the oven to 350°F. In a blender, puree the salsa and reserve.
In a large heavy skillet, heat the oil over medium high heat until hot, then stir in the on-ion, garlic, 1/2 teaspoon salt and 1/4 teaspoon pepper and cook, stirring occasionally, until golden, about 6 minutes. Stir in the chicken and cook until the chicken is cooked, about 5 minutes. Stir in the eggs and scramble with the chicken filling until the eggs are barely set, about 2 minutes. Season the filling with salt and pepper to taste.
Divide the filling between the tortillas. Roll each tortilla into a cylinder and place, side-by-side in a baking dish. Pour the salsa over the tortillas and sprinkle with the cheese.
Bake the enchiladas until the filling is hot and the cheese is melted, about 15 minutes. Serve topped with the sour cream and cilantro.