Cook onion in oil in a small saucepan over medium heat 4-5 minutes until translucent.
2Add coffee, Worcestershire sauce, ketchup, sugar and pepper and bring to a boil. Cover, reduce heat to medium-low and simmer, stirring once or twice, 15 minutes ore until slightly thickened. Let cool.
3TO GRILL: Put steak 4-6 inches above hot coals. Grill 25 - 30 minutes, turning steak and basting with glaze 4 times, until a meat thermometer inserted in thickest part reads 140 degrees F for med-rare. Let steak rest 10 minutes before slicing.
Broil steak in broiler pan rack 4-6 inches from heat source, turning and basting as directed.
5Keep any leftover glaze in a tightly covered jar for future use. It will keep several months in the refrigerator.