Three Cheese Garden Pizza

I got this one from a Pampered Chef party, so it uses Pampered Chef items.

1(13.8oz) pkg refrigerated pizza crust
1 Tbsp vegetable oil
2 garlic cloves, minced
1 C shredded cheddar cheese
1 C shredded mozzarella cheese
1/4 C grated fresh Parmesan cheese
1 tsp Italian seasoning
1 small onion, sliced into rings
2 plum tomatoes, sliced
1 medium zucchini, sliced
1 C sliced mushrooms

Preheat oven to 400. Unroll dough onto bottom of lightly greased large bar pan. Place oil in a bowl. Add garlic; bush evenly over dough. Bake crust 7 minutes. Remove from oven; place on cooling rack.
Place cheeses and Italian seasoning in bowl; mix to combine.
Sprinkle half the cheese mixture over crust; top evenly with onion, zucchini, tomatoes and mushrooms. Sprinkle with remaining cheese mixture. Bake 15-18 minutes or until crust is golden brown; remove to cooling rack. Cut into squares.