Heat oven to 450°.
Heat oil in a large nonstick skillet over medium-high heat. Add mushrooms, yellow pepper and onion; cook for 5 minutes, stirring occasionally. Place on a plate and blot with a paper towel. Set aside.
Meanwhile, unroll dough onto a baking sheet. With a floured rolling pin, roll into a 15 x 15-inch square. Place cheese sticks along the edges, cutting sticks as necessary. Roll 1 inch of dough over cheese and gently seal with a fork. Bake at 450° for 8 minutes. Remove from oven. Spread sauce evenly over pizza and sprinkle with oregano. Scatter mozzarella over pizza and top with vegetables, pepperoni and tomatoes. Bake at 450° for 8 to 10 minutes, until pizza is crisp and golden brown.
Cool for 5 minutes. Cut into 16 squares.