Heat the oven to 350 F and lightly grease a 2 1/2 to 3-quart casserole.
Heat the vegetable oil in a large skillet over medium heat. Add the ground beef and cook, undisturbed, for 4 minutes. Break the beef up, add the onions, and continue cooking for 4 to 5 minutes. Add the garlic and cook for 1 minute more.
Add the green chilies, taco seasoning, salsa, drained beans, and corn to the skillet and bring to a simmer. Taste and add salt and pepper, as needed. Reduce the heat to low and simmer for 4 to 5 minutes.
Turn half of the mixture into the prepared baking dish and top with half of the cheese and half of the chips. top with the remaining casserole mixture followed by the remaining cheese and chips.
Bake the casserole for 15 to 20 minutes or until the cheese has melted and the casserole filling is bubbling.