For sauce, in a medium saucepan cook sugar over medium-high heat until it begins to melt, shaking the pan occasionally (do not stir). Reduce heat to low; add onion and garlic. Cook and stir for 5 minutes more or until mixture is golden brown. Bring beer or water just to boiling in a small skillet. Carefully and gradually add boiling beef or water to sugar mixture, stirring constantly. Whisk in tomato paste, Worcestershire sauce, vinegar, habanero sauce, chipotle peppers, and salt. Bring to boiling; reduce heat. Simmer, uncovered, for 15 to 20 minutes or to desired consistency. Set aside.

Place steaks on the lightly oiled rack or the grill directly over medium heat. Grill for 10 to 18 minutes or until desired doneness, turning once.

Brush some of the sauce onto the steaks during the last few minutes of grilling. Pass remaining sauce with steaks. Cover and chill any remaining sauce for up to 1 week. Serve with grilled chili peppers, if desired. Makes 4 servings.

To grill chili peppers, lightly brush whole peppers with oil. Grill for 5 to 10 minutes over medium heat or until slightly charred.