BBQ Lamb and Maple Burgers

Ingredients

• 500g lamb mince
• 1 diced onion
• 1 garlic clove
• 3 tbsp pure maple syrup (preferably dark syrup for its robust taste)
• 3 tbsp whisky
• 1 egg
• Salt
• pepper
• 250g tomato sauce (or one can)
• 2 tbsp tomato paste
• 2 tbsp maple vinegar
• 2 tbsp pure maple syrup (preferably dark syrup for its robust taste)
• 2 tbsp Worcestershire sauce
• 1 tbsp garlic powder
• 1 tbsp paprika
• ½ tbsp onion powder
• ½ tbsp salt
• ½ tbsp black pepper
• 1 pinch cayenne pepper
• 5 brioche buns
• 1 sliced red onion
• 1 sliced tomato
• Lettuce broken into leaves