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.

Spice Rub: In a small bowl, stir together 4 teaspoons garlic powder; 1 teaspoon dried oregano, crushed; 1/2 teaspoon sea salt; 1/2 teaspoon sugar; 1/2 teaspoon dried thyme, crushed; 1/2 teaspoon paprika; and 1/2 teaspoon coarsely ground black pepper.

BBQ Sauce: In a 2-quart saucepan, stir together 5 cloves roasted garlic or 2 teaspoons bottled minced roasted garlic, 1 cup ketchup, 1/2 cup finely chopped celery, 1/2 cup finely chopped red onion, 1/2 cup water, 1/4 cup packed brown sugar, 1/4 cup butter, 1/4 cup Worcestershire sauce, 1/4 cup cider vinegar, 1 tablespoon chili powder, 1 teaspoon instant espresso powder, 1/2 teaspoon salt, 1/2 teaspoon ground cloves, 1/4 teaspoon cayenne pepper, and 1/4 teaspoon 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.