Stir in the flour and continue stirring for ~1-2 minutes not letting it brown.
Slowly add in your milk until smooth and thick
Stir in your salt, pepper, Italian seasoning, and garlic.
Add your parmesan cheese and stir for another ~30 seconds.
Remove from heat and stir until the cheese is melted and the sauce is smooth.
Pizza Oven
Preheat your pizza oven. Mine takes ~20-30 minutes to get up to temperature.
Vegetables
Sauté your vegetables in a pan over medium with some olive oil.
Cook until softened and with a slight char.
Assembly
Place a mixture of cornmeal and flour on your workstation for the bottom of your pizza.
Take your dough ball and stretch into the shape of a circle. This takes some practice and there are many videos on YouTube for reference! Also, an amoeba shaped pizza tastes just as good as a circle!
Ladle on your sauce (you can reheat it if it's too solid) and top with enough shredded mozzarella to cover your pizza, but not piled incredibly high.
Finally top with your browned Italian sausage and sautéed vegetables.
Cook
Place some more cornmeal onto your pizza peel and then move your pizza onto your peel. If your pizza has enough cornmeal or flour it should slide onto the peel (again watch videos on YouTube for help).
Put your peel into the oven and slowly shake the pizza forward and backwards before quickly pulling the peel away (YouTube).
Cook for ~30-45 seconds and then pull the pizza out.
Turn the pizza 180° and put back in for ~20-30 more seconds.
Take out again and if there are any parts of the pizza you want cooked more turn that part to the heat source and place back in the oven for ~5-10 seconds.
Remove the pizza from the oven and let rest for a couple of minutes.