Preheat your oven to 350°F and spray a 9x13 baking dish with nonstick cooking spray, coating the sides as well.

Line the bottom and sides of the dish with corn tortillas, overlapping slightly so there are no gaps.

In a medium saucepan over medium heat, stir together the refried beans and salsa. Cook until warmed through and smooth, then reduce the heat to low to keep warm.

In a large skillet over medium-high heat, cook the ground beef and minced onion until the beef is browned and the onion is soft, breaking up the meat as it cooks.

Sprinkle in the taco seasoning and pour in the water, stirring until the beef is evenly coated and most of the liquid has cooked off.

Stir in the roasted green chiles and corn until combined.

Spread the warmed bean mixture evenly over the prepared tortilla base.

Spoon the beef mixture on top, spreading it to the edges for even coverage.

Sprinkle shredded cheddar cheese evenly over the top.

Bake for about 20 minutes, or until the cheese is melted and the casserole is hot and bubbling.

Let rest for 10 minutes before slicing. Add your favorite toppings just before serving.