Preheat the oven to 350 degrees F. Line a rimmed baking sheet with a piece of parchment paper or a Silpat baking mat.

Spoon shredded cheddar cheese onto the prepared baking sheet using 1 tablespoon per mound. Lightly spread out, leaving 2-3 inches between each mound. You will be able to bake 6 at a time on a standard baking sheet. 

Bake until the cheese rounds are melted in the center and the edges begin to brown. Set aside to cool for 1-2 minutes but do not let harden.

Lift melted cheese rounds with a spatula and press on the back of an inverted muffin tin to form cups. The cheese will be very pliable while warm.

Allow cheese to cool and firm up before removing from the muffin tins. 

Repeat with next 6 cheese rounds.

In the meantime, add olive oil to a medium skillet. Heat over medium heat. Add ground beef and cook, stirring occasionally, until the meat is nicely browned, 5-6 minutes. Drain any excess fat.

Add cumin, smoked paprika, chili powder, and 2 tablespoons of water; season to taste with salt and pepper. Continue cooking 1-2 minutes, just until the spices become fragrant, and the meat is nice and juicy. If necessary, add an additional tablespoon of water to obtain proper consistency.

Fill taco cups with taco beef, chopped tomato, scallion, and a teaspoon of sour cream per cup. Squeeze in some lime juice over the top and enjoy!