Mediterranean Lamb Burger

• 500 g lamb mince
• 2 garlic cloves, crushed
• 2 tsp cumin
• 2 tsp oregano
• 4 wholegrain rolls
• .5 cup tzatziki
• 1 small cos lettuce
• 1 Lebanese cucumber, sliced
• .5 cup grilled capsicum (pepper)
• .5 red onion, thinly sliced