Brown ground beef over medium-low heat. Drain meat to remove any excess drippings. Add 1/4 cup of enchilada sauce into brown meat and stir until well-combined.
For Enchilada Assembly:
Preheat oven to 350º F.
Pour 1/2 cup enchilada sauce into the bottom of a 9x13 oven-safe, casserole dish.
Drizzle oil into the bottom of a skillet over a medium-low heat. Add corn tortillas, one at a time, and cook for about 1 minute each. Do not allow to become crispy.
Drain tortilla and then layer on beef, sour cream, cheese and cilantro. Roll tortilla to keep all ingredients inside. Then place seam side down in the casserole dish. Once all enchiladas have been assembled and placed into casserole dish, pour remaining enchilada sauce over to make sure well covered. Top with remaining cheese.
Place in oven and bake 15 minutes, or until cheese has fully melted.
Remove from oven and top with additional cilantro, if desired.