Barbecue Chicken Skewers (The Best)

Ingredients

• Skewers

  • ½ cup (125 ml) buttermilk
  • 1 tsp onion powder
  • 1 tsp garlic powder
  • ½ tsp ground allspice
  • ½ tsp cayenne pepper
  • 1 ½ lb (675 g) boneless, skinless chicken breast, cubed
  • 6 green onions, cut into 1 ½-inch (4 cm) pieces (optional)
  • Vegetable oil, for brushing

• Barbecue Sauce

  • ¼ cup (60 ml) ketchup
  • 2 tbsp (30 ml) water
  • 1 tbsp (15 ml) tomato paste
  • 1 tbsp (15 ml) maple syrup
  • 1 tsp sweet paprika
  • ½ tsp ground coriander
  • ¼ tsp ground allspice