In a large bowl, combine Spice Rub and steak pieces. Stir to coat steak. On eight long metal skewers, alternately thread steak, mushrooms, tomatoes, zucchini, onion, and sweet pepper.
Brush mushrooms and vegetables with olive oil. Sprinkle with salt and pepper. For a charcoal grill, grill skewers on the rack of an uncovered grill directly over medium coals for 8 to 12 minutes or until desired doneness, turning occasionally. (For a gas grill, preheat grill. Reduce heat to medium. Place skewers on grill rack over heat. Cover; grill as above.)
Serve meat and vegetables with BBQ Sauce. Makes 8 servings.
In a 2-quart saucepan, stir together roasted garlic or bottled minced roasted garlic, ketchup, celery, red onion, water, brown sugar, butter, Worcestershire sauce, cider vinegar, chili powder, instant espresso powder, salt, ground cloves, cayenne pepper, and crushed red pepper. Bring to boiling; reduce heat. Simmer, uncovered, about 25 minutes or until thickened, stirring occasionally. Cool slightly. Transfer to a blender or food processor. Cover and blend or process until smooth. Makes about 1-3/4 cups.
In a small bowl, stir together garlic powder; dried oregano, crushed; sea salt; sugar; dried thyme, crushed; paprika; and coarsely ground black pepper.