Pre-heat oven to 375F.
If you'd like your shells to be all the same size, trace about 3, 6-inch circles on the parchment paper
Measure about 1/3 cup of the cheese onto the circles and sprinkle with the onion salt
Bake for 5 minutes until the edges begin to brown
While the cheese is cooking, set up a taco shell drying station. Lay a wooden spoon across 2 soup cans and place a plate topped with a paper towel underneath. You might have to make a few taco crisping stations, or cook one shell at a time (you can do this also in a pan on medium heat, versus an oven too).
This is where you have to move fast, because as the cheese is cooling, it will harden quickly. Remove the cheese from the parchment paper using a spatula and place over the wooden spoon to crisp
Let the cheese cool and crisp up, about 5 minutes
Place on a plate and add your favorite taco fixings!