Tri-tip roast is best when cooked by dry-heat methods, such as roasting, grilling, or broiling. This lean cut becomes tough if overcooked. To ensure a juicy result, leave the fat on so it can baste and tenderize the meat while cooking, then trim it off before serving.
To achieve the doneness you want, use a meat thermometer and cook to 5 to 10 degrees below the desired temperature. Temperatures for medium rare are 145°F (63°C), for medium 160°F (71°C), and for well done 170°F (77°C). Remove roast from the oven or grill and let stand 10 to 15 minutes. The roast will continue cooking as it stands.
Tri-tip roast may be marinated or rubbed with a spice mixture before cooking. The purpose of rubs or marinades is not to tenderize this already tender cut, but to add flavoring.
To roast, place tri-tip steak in an ovenproof pan and cook in a preheated oven at 450°F (220°C) for 30 to 45 minutes, depending on desired degree of doneness. Carve the roast against the grain.
To broil, place tri-tip roast 4 to 5 inches (10–12cm) from the heat sources and broil 25 to 30 minutes, depending on desired degree of doneness. Carve the roast against the grain.
To grill, oil the tri-tip roast, or rub it with a seasoning mixture if desired, and place it over medium heat for 30 to 35 minutes, depending on desired degree of doneness. Carve the roast against the grain.