Preheat oven to 425 degrees Fahrenheit.
Roll out the thawed dough onto a greased pizza pan in the shape of a large circle.
Pre-bake the pizza dough for 5 minutes (this ensures a crispy crust). Remove from oven and spread white sauce evenly over the dough, leaving a 1-inch rim around the pizza for the crust. Sprinkle the sauce with some garlic salt, if desired.
Sprinkle the mozzarella cheese in a circle in the middle of the pizza. Then sprinkle the cheddar cheese around the mozzarella to make the pizza look like a bullseye.
Return the pizza to the oven and bake for an additional 12 minutes, or until the center bubbles and the crust is brown. Slice and serve!