Preheat oven to 350 degrees F / 177 degrees C.
On silicone baking mat or parchment paper, lay out 1 cup cheese in four small circles. Make sure cheese isn't overlapping to ensure that shells are crispy. Watch closely to prevent burning.
1 cup cheese
Remove from oven when golden brown.
Let cool for 2 to 3 minutes. While still warm, fold over cheese, into taco shell shape. Shell should harden as it cools.
Fill four shells with 6 ounces ground beef, 1 cup lettuce, 2½ tablespoons sour cream and ½ avocado.
6 ounces ground beef, 1 cup lettuce, 2½ tablespoons sour cream, ½ avocado
Serve and enjoy!