Flatten Chicken To 1/4-In. Thickness. Sprinkle With 1/4 Teaspoon Lemon-Pepper And Salt; Set Aside. In A Large Skillet, Saute Onion In Oil And Butter Until Tender. Sprinkle With The Garlic Powder And Remaining Lemon-Pepper. Remove The Onion And Keep Warm. In The Same Skillet, Cook Chicken Over Medium Heat For 3 Minutes On Each Side Or Until Browned. Spread Marmalade Over Chicken. Return Onion To The Pan. Reduce Heat; Cover And Simmer For 2-3 Minutes Or Until The Marmalade Is Melted And Chicken Juices Run Clear.