Preheat oven to 350°F. Prepare your enchilada-sauce.
In large skillet, heat oil on medium-high heat. Add onion and simmer for 3minutes, stirring periodically. Add diced chicken and green-chiles, and season with a generous pinch of pepper and salt. Saute the mix for 6-8minutes, stirring occasionally, or until the chicken is cooked through. Add the beans and stir fry until evenly blended. Remove pan from heat and set aside.
To assemble the enchiladas, create a meeting line such as: tortillas, enchilada-sauce, chicken mixture and cheese. Lay out a tortilla, and disperse 2 tbsp of sauce on the surface of the tortilla. Insert a generous spoonful of the chicken mixture in a line down the middle of the tortilla, then scatter 1/3 cup cheese. Roll up tortilla and place in a greased 9x13" baking dish.
Assemble the rest of the enchiladas. Subsequently disperse any remaining sauce evenly on the top of the enchiladas, followed by some excess cheese.
Bake uncovered for 20minutes, until the enchiladas are cooked and the tortillas are slightly crispy on the surface. Remove pan from the oven and serve the enchiladas while they are nice and hot, garnished with a great deal of toppings.
Store any leftovers in a sealed container in the fridge for up to 3 days, or freeze up to 3 months.