To make the Enchilada Sauce: 

In a small bowl, mix the tomato sauce, chicken broth, garlic, cumin, onion powder, and salt until combined. Set aside.

Heat the vegetable oil in a saucepan over medium heat. Add the flour and chili powder. Cook and whisk for 2 minutes.

Slowly add the tomato sauce mixture to the pan while whisking. Cook for 5 minutes until the sauce has slightly thickened, whisking frequently.

To assemble the Enchiladas:

Preheat oven to 350°F. 

Heat an inch of oil in a medium saucepan over medium-low heat. Using tongs, add a corn tortilla to the oil and cook for 5-10 seconds on each side. You want the tortilla to gently fry in the oil so it becomes soft and pliable. If the oil is too hot, it will fry too rapidly and become hard and crisp. Remove tortilla from oil and place on a plate lined with paper towels to get rid of excess oil. Repeat for the remaining tortillas.

Pour 1/3 of the enchilada sauce into a 9x13 inch pan and spread to coat the bottom.

Add a generous amount of cheese to the center of a tortilla (2-3 tablespoons) and sprinkle with diced onions. Roll the tortilla and place seam-side down in the pan. Repeat until all tortillas have been filled, rolled, and placed in pan.

Pour the remaining enchilada sauce over the enchiladas. Sprinkle top with remaining cheese. Cook uncovered in a 350 degree oven until hot and bubbly, around 20 minutes. Serve with chopped cilantro, additional diced onions, and sour cream. Enjoy!