Preheat oven to 425° F. In a pan, season beef with salt and pepper and cook in a little olive oil, until no longer pink. Remove from pan and set aside. In the same pan, add peppers and onion and cook until softened.
On a lightly floured surface, roll out the crust. Transfer to a lightly greased baking sheet.
Spread the alfredo sauce over the crust in an even layer. Top with cheeses, meat, and vegetables. Bake for about 15-20 minutes, or until the crust is golden brown and the cheese is bubbly.