Place a large skillet over medium heat and add the oil. Once hot, add the onion and garlic. Cook, stirring frequently until softened, about 2-3 minutes.
Add the ground beef and cook until browned, about 5-6 minutes. Break up the meat as it cooks.
Stir in the black beans, salsa, and corn. Cook for an additional 4-5 minutes, or until most of the liquid is gone.
Transfer the contents of the skillet to a 9-inch x 13-inch casserole dish. Then top with the cheese and finally the Fritos.
Bake for 25 minutes, or until filling is bubbly and the cheese is melted.
Remove from the oven and serve warm. I like to sprinkle some parsley on top and add a dollop of sour cream.