Let it Rest. Before cooking, remove the tri-tip from the refrigerator and allow at least 10 minutes before placing on the grill or in the oven. After roasting or grilling, remove the tri-tip from the heat and place it on a warm plate or serving platter. Cover the meat loosely with foil and let it rest for 10 to 15 minutes. Cut across the grain. This will minimize the loss of juices and give you the most tenderness.