Heat oven to 400˚F. Line a large baking sheet with foil. Lightly form dough into a ball on clean surface; let rest 10 minutes. Place broccoli in small glass bowl with 2 tablespoons water. Microwave on HIGH for about 2 minutes or until just tender; drain and cool.
Press or roll dough out into an irregular round, 10 to 11 inches in diameter, on baking sheet.
Bake crust 4 to 6 minutes or until edges begin to set.
Spread mashed potatoes evenly on crust. Top with broccoli and tomatoes. Bake about 20 minutes or until crust is golden brown. Sprinkle with cheese; bake 5 to 10 minutes longer until cheese is melted. Sprinkle with green onions and cut into wedges.