Tri-Tip roasts are lean and best prepared similarly to Eye-of-Round roasts. This is a lean cut, so it will not tolerate overcooking (dry if overcooked). The tapering, triangular shape of the Tri-Tip means that it perfect for the family that prefers different levels of done-ness. When the thicker part is up to medium rare temp the narrower end will be medium well or well done.
If you’re very careful and can regulate the temperature, these can also be done on the grill. More often they’re thick enough that roasting in an oven is the better cooking method unless you’re confident.