Soak wooden skewers in water for 30 minutes. Meanwhile, light a hot fire in a charcoal or gas grill. Slice the beef across the grain into thin strips. Carefully ease the beef strips onto skewers, snaking each strip so it looks like a series of S's on the skewer. You may have more than one strip of beef per skewer. Place the beef onto a large plate or platter.
Whisk together the barbecue sauce, lemon juice, crushed garlic, red and black pepper and salt in a bowl. Set aside half of sauce. Pour or brush the remaining sauce evenly over the beef and allow to marinate for 5 to 10 minutes, then discard.
Place the skewers on the grill and cover. After 3 minutes, flip skewers, brushing meat with some of the reserved sauce; cover and cook for 3 more minutes, until meat is done. Serve with remaining sauce.