Preheat Oven:
Preheat your oven to 350°F (175°C).

Cook Ground Beef:
In a skillet over medium heat, cook the ground beef until browned and fully cooked. Drain any excess fat.

Add Seasoning and Tomatoes:
Stir in the taco seasoning and the can of diced tomatoes with green chiles (undrained). Cook for an additional 5 minutes, allowing the flavors to blend.

Prepare Filling Mixture:
In a large bowl, combine the cooked beef mixture with the shredded cheddar cheese and ranch dressing. Mix thoroughly until well combined.

Assemble Bites:
Place the frozen phyllo tart shells on a baking sheet. Spoon the beef and cheese mixture into each shell, filling them generously but not overflowing.

Bake:
Bake in the preheated oven for 8–10 minutes, or until the cheese is melted and the tart shells are golden brown.

Serve:
Remove from the oven and let cool slightly before serving. Enjoy these bites warm.