Taco Enchiladas with Cheese Sauce

ground beef

packet taco seasoning or homemade mix

corn

chopped onion

butter

all-purpose flour

+ ½ cups milk

Ro-tel diced tomatoes & green chiles, drained

shredded sharp cheddar cheese, divided

salt and pepper

about 12 (6-inch) corn or flour tortillas, plus more if needed (flour ones are easier to work with)

shredded lettuce

sour cream

chopped tomatoes & avocado, optional