Preheat your oven to 450°F and line a baking sheet with a silicone mat or lightly grease it, then sprinkle with cornmeal.
In a saucepan, melt the butter over medium heat, then stir in the roasted garlic and cook for 1 minute.
Add the flour to the saucepan and whisk for 1 minute to create a roux.
Gradually pour in the skim milk and half and half while whisking constantly. Add the black pepper and simmer, stirring until the mixture thickens, which should take about 3 minutes.
Remove the saucepan from heat and stir in the Parmesan cheese until the sauce is smooth.
Roll out the pizza dough into a 12-inch circle and place it on the prepared baking sheet.
Spread the white sauce evenly over the dough. Top it with the shredded chicken, diced red onion, and mozzarella cheese.
Bake the pizza for 17 minutes, or until the crust is golden brown and the cheese is bubbling and lightly browned.
Once removed from the oven, sprinkle the pizza with fresh thyme, oregano, and parsley. Slice and serve hot.