Preparation

• Heat the oven to 350ºF.
• Heat 1 tablespoon neutral oil in a large skillet over medium-high heat until shimmering. Add finely chopped onion and diced red bell pepper and cook, stirring occasionally, until the onions are translucent and slightly softened, about 4 minutes.
• Add lean ground beef and cook, breaking it up into small pieces with a wooden spoon, until cooked through and browned, 6 to 8 minutes. Stir in tomato paste and taco seasoning. Cook until fragrant and the tomato paste is slightly darkened, about 2 minutes.
• Stir in frozen corn kernels and drained diced green chiles, scraping up any browned bits from the bottom of the pan. Remove the pan from the heat.
• Reserve 1 cup enchilada sauce from the cans. Stir the remaining enchilada sauce into the beef mixture. Taste and season with kosher salt as needed.
• Mix shredded Monterey Jack and shredded mild cheddar cheese together in a medium bowl.
• Spread ½ cup of the reserved enchilada sauce in the bottom of a 9x13-inch baking dish. Arrange 6 of the corn tortillas in an even layer on top (they can overlap). Dollop and spread ½ of the refried beans evenly over the tortillas. Spread half of the beef mixture over the beans, then sprinkle with ⅓ of the cheeses. Repeat layering the tortillas, refried beans, beef mixture, and cheeses. Top with the remaining 6 tortillas. Spread the remaining ½ cup enchilada sauce over the tortillas, then sprinkle with the remaining cheese.
• Place the baking dish on a rimmed baking sheet. Bake until the cheeses are melted and the filling is bubbling, 30 to 35 minutes. Let cool for 10 minutes before serving. Serve with desired toppings.