Preheat oven to 450 degrees. In large skillet over medium heat, in hot oil, cook mushrooms, peppers and onion 10 minutes or until vegetables are softened, stirring frequently.
Place pizza crust on large baking sheet.
Spread roast beef spread evenly over crust. Spread pizza sauce evenly over beef spread. Spoon vegetables onto pizza. Spoon cheese dip by teaspoonfuls over vegetables.
Bake 10 minutes or until crust is crispy and topping is heated through.