Preheat oven to 375F.

In a skillet over medium-high heat, brown the ground beef - stirring frequently.

Turn off heat and drain excess grease.

Add remaining ingredients and stir to mix thoroughly.

Cut low carb tortillas into squares (cut off rounded edges), then cut into quarters.

Using 2 tortilla squares at a time to line muffin cups.

Add 1/4 cup of meat mix and 2 tbsp of shredded cheese to each cup.

Add a single tortilla square to the top of each cup, pressing in slightly.

Add 2 tbsp of meat and another 1 tbsp of cheese.

Brush oil onto the top of the tortillas that are exposed.

Bake 15-20 min, until tortilla tops are are browned and cheese is bubbling.

After removing from oven, let cool for a few minutes and carefully transfer taco cups to plates.

Serve immediately with sour cream.