1) Stir any liquid into the sourdough starter, and spoon 1 cup starter into a mixing bowl.
2) Add the hot water, flour, salt, yeast, and Pizza Dough Flavor. Mix to combine, then knead till smooth and slightly sticky, about 7 minutes at medium speed using a stand mixer with dough hook. Place the kneaded dough in a lightly greased container, and allow it to rise till it's just about doubled in bulk. This might take 2 to 4 hours; it might take more. A lot depends on how vigorous your starter is. For a faster rise, place the dough somewhere warm (or increase the yeast). To slow it down, put it somewhere cool.
3) For two thinner-crust pizzas, divide the dough in half, shaping each half into a flattened disk. Drizzle two 12" round pizza pans with olive oil, tilting the pans to coat the bottom. Place half the dough in each pan. Cover, and let rest for 15 minutes. Gently press the dough towards the edges of the pans; when it starts to shrink back, cover it, and let it rest again, for about 15 minutes. Finish pressing the dough to the edges of the pans.
4) For a thicker-crust pizza, drizzle olive oil into a jelly roll pan (10" x 15") or half-sheet pan (18" x 13"), or similar sized pan; or a 14" round pizza pan, tilting the pan to coat with the oil. Shape the dough into a flattened disk or oval. Place it in the pan, cover it, and let it rest for 15 minutes. Push the dough towards the edges of the pan; when it starts to fight back, cover it and let it rest for 15 minutes. Finish pushing it to the edges of the pan.
5) Cover the pan, and let the dough rise till it's as thick as you like. For thin-crust pizza made from fairly fresh starter, this may only be an hour or so. For thick-crust, using an old, little-used starter, this may take most of the day. There are no hard-and-fast rules here; it all depends on the vigor of your starter, and how you like your crust. Once you make it a couple of times, you'll figure out what time frame works for you.
6) Towards the end of the rising time, preheat your oven to 450°F.
7) For a thicker crust, pre-bake the crust for about 8 minutes before topping. Top, then bake till toppings are hot and cheese is melted and bubbly, about 10 minutes. For thin crusts, bake for 4 to 5 minutes, then top and bake for an additional 8 to 10 minutes, or till toppings are as done as you like.
8) Remove from the oven, and loosen the edges of the pizza with a table knife or heatproof spatula. Carefully lift it onto a cooling rack; you can serve it right from the pan, if desired, but a cooling rack helps keep its bottom crisp. Serve hot.
Yield: one 14" round, or rectangular thick-crust pizza; or two 12" round thin-crust pizzas.
Be aware of some sourdough dynamics here. The less-used your starter, the more liquid on top, the more sour it's likely to be; using a starter that hasn't been fed for weeks will yield a pizza crust that rises slowly, and tastes quite tangy. This type of crust is handy when you want to make dough in the morning, and have pizza ready for dinner. On the other hand, a starter that's fed regularly will yield a less-sour crust, one that will rise much more quickly. This is a great "weekend" crust, as you can shape it at 8 a.m., and have pizza for lunch.