Preparation Preheat oven to 400°F. Unfold crust on lightly floured rimless baking sheet. Fold 1/2 inch of edge over; crimp decoratively. Spread crust with mustard; sprinkle with half of Brie. Top with tomatoes, then olives. Sprinkle with onion, remaining Brie, and oregano, then Parmesan cheese. Bake pizza until crust is crisp and cheeses melt, about 20 minutes.
Preparation Preheat oven to 400°F. Unfold crust on lightly floured rimless baking sheet. Fold 1/2 inch of edge over; crimp decoratively. Spread crust with mustard; sprinkle with half of Brie. Top with tomatoes, then olives. Sprinkle with onion, remaining Brie, and oregano, then Parmesan cheese. Bake pizza until crust is crisp and cheeses melt, about 20 minutes.