In a large frypan over medium-high heat brown the beef mince and stir in the taco seasoning and tomatoes. Line a 20x30cm baking dish with half the tortillas. Spoon the beef mixture into the dish then top with the remaining tortillas. Spread salsa over the tortillas and sprinkle with the cheese.
Bake for 20 to 30 minutes, or until cheese is melted and bubbly.