Brown ground beef and drain, add taco seasonings as you would for tacos, but omit the water.
Once mixed, add diced tomatoes, and refried beans. mix well.
In a 13x9 inch pan, spread about 1 to 2 cups beef mixture in the bottom of the pan, layer 1/4 jar of salsa,1 cup cheese, 1 cup corn, 1/3 the onions, 1/4 the peppers and 1/4 of the crushed taco shells. place 2 and 1/2 flour tortillas on top.
Start layering again starting with the beef mixture. making 2 more layers ending in flour tortillas.
On the final layer spread salsa, crushed corn shells, peppers and cheese.
Place on cookie sheet and bake in the oven at 350 for about 20 min until the cheese has melted and it's bubbly.