Preheat oven to 350ºF.

In a skillet, cook ground beef until no longer pink. Drain fat.

Add taco seasoning and diced tomatoes and green chiles. Stir and cook for 5 minutes. Remove from heat.

Combine shredded cheddar cheese, Ranch dressing, and taco meat.

Spoon taco meat mixture into frozen phyllo tart shells. You can freeze for later at this point.

Bake for 8-10 minutes, until cheese melts. (Add 2-3 minutes to the baking time if baking frozen tarts).