Trim off any large deposits of fat surrounding the tri-tip. For grilling you want a little bit of fat, but nothing larger than ½-inch thick.

Coat tri-tip with salt and pepper and place in a large resealable plastic bag.

Pour in whiskey and apple cider vinegar.

Marinate in refrigerator for at least 3 hours and up to 12 hours.

About 30 minutes prior to cooking remove meat from the marinade and discard the marinade. Allow meat to rest at room temperature.

For oven roasting, preheat the oven to 450º F.

Place the tri-tip fat side up on a rack in a shallow roasting pan.

Roast for 30 minutes and begin checking the internal temperature on a meat thermometer: for medium-rare, 135º-140º F and 140º-145º F for medium.

If grilling, heat grill to 275ºF temperature and place roast on the grill, fat side up. Close grill and cook until the temperature of the meat reaches 135ºF inside. Remove roast from grill and place meat directly on the coals and sears each of the roast

Transfer roast to a platter and let rest 10 minutes.

Slice thinly across the grain and serve immediately.