Place a pizza stone or heavy baking sheet in oven. Preheat oven to 500° (keep stone or baking sheet in oven).
Heat a large cast-iron skillet over medium-high heat. Sprinkle steak with 1/2 teaspoon pepper. Coat pan with cooking spray. Add steak to pan; cook 4 minutes on each side or until desired degree of doneness. Remove from pan; let stand 5 minutes. Cut steak across the grain into very thin slices.
While steak cooks, place dough in a medium microwave-safe bowl coated with cooking spray. Cover and microwave at MEDIUM (50% power) for 45 seconds. Let stand 5 minutes. Roll dough into a 14-inch circle on a floured surface; pierce liberally with a fork. Carefully remove pizza stone from oven, and sprinkle with cornmeal. Arrange dough on pizza stone. Bake at 500° for 10 minutes or until browned and crisp.
While crust bakes, return skillet to medium-high heat. Add oil; swirl to coat. Add onion and bell peppers; sauté 3 minutes. Add garlic; sauté 2 minutes. Add steak; sauté 30 seconds or until thoroughly heated. Remove from heat; stir in remaining 1/2 teaspoon black pepper and soy sauce. Arrange steak mixture over crust.
Combine milk and flour in a 4-cup glass measuring cup; stir with a whisk until smooth. Microwave at HIGH 2 minutes or until thickened, stirring every 30 seconds. Stir in cheese and remaining ingredients. Drizzle cheese mixture over pizza. Cut into 8 wedges.