Preheat oven to 425°F. Drain chicken. Place pizza crust on pizza pan; spread evenly with barbecue sauce and sprinkle with mozzarella. Top with chicken, red onion and mush-rooms. Bake on lowest rack in oven for 15 to 20 minutes or until crust is golden brown and cheese is melted and bubbling. Garnish with green onion and sesame seeds.