Step 1

Preheat the oven to 350°F with a rack in the center position.

Step 2

Make the enchilada sauce. Place the oil and flour in a medium saucepan. Cook, whisking constantly, over medium heat until smooth, about 6 minutes. Once bubbling, whisk in the chili powder, garlic powder, onion powder, cumin, oregano, and tomato paste. Once combined, slowly whisk in chicken stock and salt and bring to a simmer. Once simmering, reduce the heat to low and cook, stirring occasionally, for about 5 minutes, or until slightly thickened.

Step 3

Meanwhile, make the casserole. Heat a large skillet over medium heat. Add the ground beef, salt and pepper and cook, breaking it up with a wooden spoon, until browned, about 8-10 minutes. Add the onion and bell pepper and cook until softened, about 5 minutes. Stir in the garlic and cook until fragrant, 1 minute more. Stir in the green chiles, beans, corn and ½ of the enchilada sauce and cook until warmed through, about 5 more minutes. Remove from heat.

Step 4

Dip half of the tortillas in the enchilada sauce, then arrange in a single layer on the bottom of a 9-x13-inch baking dish. Top with half of the beef filling and half of the pepper jack and cheddar. Dip the remaining tortillas in the remaining enchilada sauce and arrange in a single layer on top of the cheese. Top with the remaining filling and remaining cheese. Cover with foil and bake for 20 minutes. Remove from the oven and uncover. Return to the oven for another 15 minutes, or until the cheese is bubbly and golden.

Step 5

Serve with pico de gallo, pickled onions, and sour cream if using.