Preheat oven to 450°.
Place a nonstick skillet over medium-high heat until hot. While pan heats, combine chili powder and garlic powder; sprinkle over both sides of steak. Add steak to pan; cook 4 minutes on each side. Remove steak from pan; let stand 5 minutes. Slice steak diagonally across grain into 1/4-inch slices.
Lightly coat pizza crust with cooking spray; spread salsa evenly over crust. Arrange pepper and onion evenly over salsa. Top with steak strips; sprinkle with cheese. Bake at 450° for 8 to 10 minutes. Cut into 8 slices.