1. Preheat oven to 450 degrees. Rub a large rimless baking sheet (or a rimmed one, upside down) with oil.
2. On a lightly floured work surface, use a rolling pin and your hands to roll and stretch dough into a 15-by-11-inch rectangle (if dough becomes too elastic to work with, let it rest a few minutes). Transfer to prepared sheet.
3. Spread sauce evenly over dough, leaving a 1-inch border all around. Top with provolone, tomatoes, and if desired, onion; scatter beef over top. Season with salt and pepper.
4. Bake until crust is golden, beef is cooked, and cheese is melted, about 20 minutes. Serve immediately.

Serves 4.