Beef Chapli Kebab Burger

Ingredients

• 2 red onions, grated
• 3 tbsps finely chopped coriander
• 2 tbsps garlic and ginger paste
• 3 green bird’s eye chillies, very finely chopped
• 1 tbsp dried red chilli flakes
• 1 tsp Kashmiri chilli powder
• 1 tbsp cumin seeds, coarsely ground
• 1 tbsp coriander seeds, coarsely ground
• 1 tsp garam masala
• 1 tsp ground black pepper
• 1⁄2 tsp salt, plus extra to taste
• 2 tbsps gram flour
• 800g minced beef (preferably 20% fat)
• 200g beef bone marrow, finely chopped
• 3 tomatoes, peeled, deseeded
• 2 tbsps rapeseed oil
• 12 slices of burger cheese
• Green chutney
• 6 burger buns, buttered and toasted
• Iceberg lettuce leaves
• Sliced tomato
• Sliced onion