Preheat the oven to 350 degrees F (180 degrees C).
Peel and cut Potato (1 pound) into small cubes.
Chop Mushroom (1 pound) into small pieces.
Dice Onion (1/2) and Red Bell Pepper (1/2).
In a medium saucepan, mix Enchilada Sauce Mix (1 packet), Water (1 1/2 cup), and Tomato Sauce (1 can) together. Bring to a boil, reduce heat to medium-low and simmer for 5 minutes or until thickened. Set aside to cool.
In a large skillet over medium-high heat, saute potato in Olive Oil (3 tablespoon) and season with Salt (to taste) and Ground Black Pepper (to taste). Cook for about 3 minutes, or until they begin to get tender.
Add in mushroom, bell pepper, and onion, cook until vegetables are softened, about 5 minutes.
Add in Black Beans (1 can) and ⅔ of the Shredded Cheddar Cheese (1 1/4 cup), mix well. Remove from the heat and set aside.
Spread a thin layer of sauce on the bottom of the baking dish.
To assemble the enchiladas, spread two tablespoons of the sauce on a Flour Tortilla (8), add a small handful of the filling in a line down the center, roll up the tortilla.
Place all enchiladas on the baking dish.
Spread the remaining sauce evenly on top of the enchiladas and sprinkle with the remaining Shredded Cheddar Cheese (3/4 cup).
Bake in the oven for 20 minutes or until the cheese is melted and the edges of the tortilla are slightly crispy. Serve hot with Fresh Cilantro (to taste), Sour Cream (to taste), or toppings of choice.