Preheat your oven to 350°F (175°C) and gather your ingredients and equipment.

In a large skillet over medium heat, brown the lean ground beef for 6-8 minutes, then drain excess fat.

Stir in taco seasoning and undrained diced tomatoes and green chiles. Simmer for 5 minutes.

Mix shredded cheddar cheese with ranch dressing until blended, then fold in the beef mixture.

Place phyllo tart shells on a baking sheet, fill each with the mixture, being careful not to overfill.

Bake for 8-10 minutes if shells are fresh or 10-13 minutes if frozen, until golden brown.

Cool for a few minutes before serving, possibly with dips like guacamole or pico de gallo.