12 pounds beef sirloin In small bowl, whisk together mustard, vinegar, soy sauce, honey, rosemary, paprika, garlic, salt, pepper and cayenne pepper.
2Cover and let stand at room temperature for at least 1 hour to blend flavors.
3Trim meat if needed and cut into 1 1/2 inch pieces. Transfer to large bowl.
4Spoon half of mustard mixture over beef, toss gently to coat. Place in zipper plastic bag and marinate for least an hour in the refrigerator.
5On 10-inch skewers, thread meat, leaving 1/4 inch between pieces.
7Reduce heat to medium (on a gas grill). Place meat skewers on grill rack over heat. Cover and grill 8 to 10 minutes or until meat reaches desired doneness, turning once and brushing with remaining mustard mixture halfway through grilling.