Preheat oven to 500ºF. If you have a pizza stone, put it on the bottom rack of your oven. Bring the pizza dough to room temperature.

Bring a small pot of water to a boil. Remove from heat and add the sundried tomatoes. Let sit for 10 minutes, or until the tomatoes are soft and plump. Drain and chop the tomatoes.

In a small bowl, combine the olive oil, garlic, and lemon juice.

Divide the dough into two portions; shape each portion into a round about 1/4 inch thick. Brush with the garlic oil. Scatter half the tomatoes over each dough portion. Top with a single layer of zucchini slices, then with red onion. Scatter the cheeses over the top and sprinkle with red pepper flakes.

Carefully transfer the pizzas to the preheated pizza stone or to a heavy duty baking sheet. Bake 10-12 minutes, or until the cheese is melted and the edges of the dough are puffed and charred. Serve with additional red pepper flakes.