For the sauce:
1 tablespoon olive oil
1/2 cup finely diced red onion
1 teaspoon minced garlic
1/2 cup chicken broth
1/4 cup ketchup
1/4 cup steak sauce
1 tablespoon finely chopped fresh parsley
1 tablespoon Worcestershire sauce
1-1/2 teaspoon ground coffee
1/4 teaspoon freshly ground black pepper
For the rub:
1 tablespoon cracked black pepper
2 teaspoons garlic salt
1 teaspoon dry mustard
1 teaspoon paprika
1/4 teaspoon cayenne pepper
2 to 2-1/2 pounds tri-tip beef, about 1-1/2 inches thick
12 slices French bread
Oak, mesquite, or hickory chips soaked in water for at least 30 minutes
1. To make the barbecue sauce: In a medium saucepan over medium-high heat, warm the olive oil. Add the onion and garlic and cook, stirring occasionally, until soft, about 5 minutes. Add the chicken broth, ketchup, steak sauce, parsley, Worcestershire sauce, ground coffee, and black pepper. Bring the mixture to a boil, then reduce the heat to a simmer and cook, stirring occasionally, until reduced to 1/2 cup, about 10 minutes. Purйe the sauce in a food processor or blender. Allow to cool, cover and refrigerate until ready to use. Bring to room temperature before serving.
2. To make the dry rub: In a small bowl, mix together the black pepper, garlic salt, mustard, paprika, and cayenne. Press the mixture into the surface of the tri-tip, cover with plastic wrap, and refrigerate for 3 hours or as long as 24 hours.
3. Follow the grill`s instructions for using wood chips. Sear the tri-tip directly over medium heat, turning once, until both sides are seared, about 5 minutes total. Then grill the tri-tip indirectly over medium heat, turning once, until the internal temperature is about 140 F for medium-rare, 20 to 30 minutes more. Allow to rest for 5 minutes before slicing thinly on the diagonal against the grain.
4. Build each sandwich with slices of meat and a dollop of sauce. Serve warm or at room temperature.