It's a simple recipe that doesn't even require a smoker or grill. Tri tip is coated with a simple spice rub and baked in the oven until it's nearly cooked through, then it's finished in a hot cast iron pan for a beautifully browned sear.
In a small mixing bowl whisk together salt, pepper, ancho chili powder, smoked paprika and garlic powder. Rub over entire tri tip coating every surface.
Let it rest at room temperature for 1 hour, or cover and refrigerate up to 24 hours then let rest at room temperature 1 hour. During last 15 minutes of resting preheat oven to 350 degrees.
Place roast on an oven safe wire cooling rack then place rack over a rimmed baking sheet.
Insert an oven safe food probe thermometer into roast into center of thickest portion. Set thermometer about 5 degrees shy of desired doneness temperature.
Bake tri tip in preheated oven until it is about 5 degrees shy of target temperature,** about 40 to 55 minutes (bake time will vary quite a bit based on thickness of roast and desired doneness).
Near the end of baking preheat a cast iron skillet over medium-high heat on the stovetop for about 5 minutes. Turn on exhaust fan.
Add 1 Tbsp vegetable oil to the skillet.
Sear the tri tip in the skillet until evenly browned all sides about 4 to 6 minutes total (it should rise about 5 more degrees while searing), and tri tip has reached desired doneness (I like about 130 to 135°F).
Transfer to a cutting board, tent with foil and let rest 10 minutes (it should rise about 5 more degrees). Slice thin then serve.
*Look for a tri tip that's a few inches thick and fairly even in size through the length so it cooks more evenly. Also look for one well marbled with fat for a more tender texture.
If the tri tip has silver skin if it is still attached but leave excess fat for moisture (unless there's a big slab of fat you can trim some of that away).
**Final target temps to watch for at the end of searing are 120 to 125°F for rare, 130°F for medium-rare, 135 to 140°F for medium.
Note for food safety that the FDA recommends tri tip should be cooked to an internal temperature of 145 degrees and a 3 minute rest time. Consuming raw or undercooked meats, poultry, seafood, shellfish, or eggs may increase your risk of foodborne illness.