Mix all ingredients in a large bowl and toss the cheeses with the flour and garlic salt, to coat, and blend.
Line a cookie sheet with Parchment paper, and place about 1/3 cup of the cheese mixture on the parchment paper, and smooth the cheese mixture out into a circle about 5 inches by 5 inches.
You should be able to get 3 cheese circles per cookie sheet.
Bake them at 350 degrees for about 15 minutes, and then remove them from the oven. Take them off the cookie sheet one at a time, and immediately place them into the middle of the taco holder, and gently push the center of the shell down to form the taco shell.
I removed the cheese shells from the cookie sheet with a large spatula and had another spatula to help place it in the taco holder, and gently push down the center to form the shell.
Repeat these steps, until all shells have been baked and formed.
Let the shells cool completely, and then place them on a tray until time to serve. Fill with your favorite taco ingredients, and Enjoy!