Heat oven to 400 degrees. Heat oil in a skillet over medium heat. Add broccoli and sliced onion; sauté 5 minutes, until onion is soft. Add sliced garlic; sauté 2 minutes. Stir in salt and pepper.
Place crust (which should be approximately 10.5 ounces) on a baking sheet. Scatter about 1/2 cup cheese on top. Slice tomato and distribute with broccoli mixture on top, then scatter more cheese over it. Repeat with second crust.
Bake at 400 degrees for 12 minutes. Slice each into 6 pieces.