1. Preheat oven to 425°.
2. Heat oil in a large nonstick skillet over medium-high heat. Add garlic and burger; sauté until burger is thawed. Add onion, mushrooms, and bell pepper; sauté 2 minutes. Remove from heat; sprinkle with salt.
3. Lightly coat pizza crust with cooking spray; place on an ungreased baking sheet. Spoon marinara sauce onto crust; spread over crust, leaving a 1-inch border around outside edge. Top with burger mixture; sprinkle with cheese.
4. Bake at 425° for 12 minutes or until crust is golden and cheese melts. Cut into 6 slices.