Crust: Add warm water, yeast, salt, and oil to stand mixer. Mix well. Add kneading attachment to mixer and add flour to the bowl. Turn the mixer on low until flour is incorporated. Increase mixer speed to medium for 10-15 minutes. When dough is ready, the sides of the bowl will be clean. Put the dough into a large, greased bowl and let it proof until doubled in size.
Sauce: Put 1 tablespoon of olive oil into a preheated sauce pan. Add onions and a little kosher salt. Saute for about 5 minutes, then add garlic. Continue to saute until onions are very soft and starting to caramelize. Add the other tablespoon of oil and the tablespoon of flour. Cook for 2-3 minutes. Add milk while whisking constantly. Turn heat to high and bring to a boil, then immediately reduce to a simmer. Season with nutmeg, salt and pepper. Continue to simmer until dough is ready.
Preheat oven to the highest possible temperature (usually around 550F).
Spread a pizza stone with cornmeal. Turn the dough out onto the stone and stretch it to fit the size of the stone. Pre-bake it until it just starts to lightly brown.
Remove dough from oven and top with sauce, Parmesan, spinach, artichokes, and Mozzerella cheese. Return to oven and bake until cheese is melted and pizza is browned around the edges.