Melt butter in a small saucepan over medium heat. Whisk in flour until smooth. Cook, stirring, for 2 minutes.
Gradually whisk in milk and cook for a few minutes until slightly thickened. Add salt, pepper, garlic and basil.
Mix in Parmesan cheese and stir until the cheese has melted.
Remove from heat. Sauce will thicken as it stands.
For one regular pizza crust (using homemade dough) I like to pre-bake the dough for 5 minutes at 475 degrees F., before adding the toppings.
After 5 minutes in the oven, remove the crust. Spread crust with an even, smooth layer of white garlic sauce. Sprinkle with cheese, chicken, vegetables, and more cheese on top.
Return to oven at 475 degrees F for about 10-12 more minutes, or until golden brown.