Preheat your oven to 350 degrees. Spray a 9 by 13 inch baking dish with cooking spray and set aside.
In a large skillet for the enchilada sauce, heat 1 tablespoon oil over medium heat. Add 1 diced onion and 1/2 teaspoon kosher salt. Sauté until the onion is translucent, about 5 minutes.
Stir chili powder and cumin into the onion for the enchilada sauce and cook for about thirty seconds. Then stir in 1 tablespoon all purpose flour. Slowly whisk in vegetable stock. Then stir in the tomato sauce and minced garlic. Bring to a simmer and cook, stirring occasionally for 5 minutes.
Transfer the enchilada sauce to a blender and blend to make smooth (optional). Pour 1/2 cup in the bottom of the prepared baking dish. Add the rest of the enchilada sauce back to the skillet you cooked it in.
In a large bowl, combine the black beans, sweet potatoes, salt, pepper, chiles, chili powder, cumin, garlic, and 1 cup of cheese.
Working with one tortilla at a time, dip it in the enchilada sauce. Then add 1/4 cup of the black bean filling. Roll and place seam side down in the prepared baking dish. Continue with all 10 tortillas. Pour the remaining enchilada sauce over the top, and then top with the remaining cheese.
Bake uncovered for 20 minutes or until the cheese is bubbly.