Place rack in lowest position. Heat oven to 425 degrees F. Unroll crust on greased 15 x 10 x 2-inch baking pan.
Bake on lowest position in 425 degree F oven 10 minutes, until puffed, dry to the touch and lightly golden.
Meanwhile, cook sausage in skillet 5 minutes, until no longer pink. Add onion and seasoning; cook 2 minutes. Remove from heat.
Spread crust with marinara sauce. With slotted spoon, transfer sausage mixture to crust. Top with Monterey Jack and Parmesan.
Bake in 425 degree F oven 8 to 10 minutes, until cheese is melted, crust is browned. Let cool for 5 minutes. Makes 8 servings.