PREPARATION
Preheat oven to 450°.
Heat olive oil in a large nonstick skillet over medium heat and cook onion, stirring occasionally, until caramelized, about 20 minutes. Stir in milk, Knorr® Four Cheese sauce mix and rosemary and bring to a boil, stirring constantly. Reduce heat and simmer, stirring frequently, about 3 minutes.
Arrange pizza crust on baking sheet. Evenly top crust with 1/2 of the sauce mixture, potatoes, then remaining sauce mixture, leaving 1/2-inch edge. Sprinkle with cheese and bake for 15 minutes or until crust is golden. Enjoy a slice or the whole pie!