What to buy: Harissa is a fiery Tunisian spice paste that ranges in consistency from smooth to slightly chunky. It’s available in tubes and jars in many Middle Eastern and gourmet markets, or online. You can also make your own.
1In a nonreactive bowl, stir together harissa, vinegar, salt, pepper, 1/4 cup of the olive oil, and garlic until well blended. Rub marinade all over tri-tip, coating it well. Place tri-tip in a nonreactive dish and cover with plastic wrap or put the roast in a large resealable plastic bag. Allow to marinate in the refrigerator 8 to 12 hours.
2Heat the oven to 375°F and arrange a rack in the middle. Remove tri-tip from the refrigerator and let sit at room temperature for 30 minutes.
3Heat remaining 1 tablespoon olive oil in a large ovenproof frying pan over medium-high heat. Sear tri-tip for about 2 minutes per side or until nicely browned. Place the frying pan in the oven and roast tri-tip until it reaches an internal temperature of 125°F for medium rare, about 20 to 22 minutes.
4Remove tri-tip from the oven and cover loosely with foil. Let rest 15 minutes before carving. Slice across the grain and serve.
Beverage pairing:Massena Moonlight Run GSM, Barossa Valley, Australia. A lushly fruited red with a good dose of aromatic spice is a solid match with the tri-tip. Wines like this can be found in Australia’s Barossa Valley. GSM stands for the blend of Grenache, Syrah, and Mourvèdre grapes.