In A Large Nonstick Skillet, Cook The Leeks In Oil Over Medium Heat For 4-5 Minutes Or Until Lightly Browned, Stirring Occasionally. Remove And Set Aside. Crumble Sausage Into The Same Skillet. Cook Over Medium Heat Until No Longer Pink; Drain. Place The Crust On An Ungreased Baking Sheet Or 12-In. Pizza Pan. Spread With Pizza Sauce; Top With Leeks, Sausage, Onion And Cheese. Bake At 450 Degrees F For 10 Minutes Or Until Cheese Just Begins To Brown.