Preheat oven to 350F, line two large baking sheets with parchment paper.

In a medium bowl, mix together cheddar and Parmesan cheeses. Arrange into 6 roughly equal piles on the baking pans - 3 per pan, spread out from each other and the sides.

Arrange the cheese in each pile into a 6" round, roughly even thickness throughout.

Bake for 6-8 minutes, or until cheese has melted and the edges have browned. Remove from oven and allow to partially cool, about 2 minutes.

Carefully lift each cheese round with a silicone spatula, drape over your prepared spoon handle / glasses setup.

Allow the taco shells to fully cool.

Remove taco shells from the suspended spoons, put 3 on each plate.

Fill cheese taco shells with your desired taco toppings. Serve immediately.