BBC Food - Recipes - Tandoori king prawns with butter sauce

Ingredients

• 1 tsp garam masala
• ½ tsp ground cinnamon
• 1 tsp chilli powder
• 1 tsp ground cumin
• 2 garlic cloves, crushed
• 5cm/2in piece fresh ginger , finely grated
• 200ml/7fl oz plain yoghurt
• 500g/1lb 2oz large tiger prawns , peeled and de-veined, tails left on
• 2 lemons , cut in half
• 50g/1¾oz butter
• 1 red onion , finely chopped
• 2 garlic cloves, finely chopped
• 1 red chilli , finely chopped
• 3 ripe tomatoes , roughly chopped
• 200ml/7fl oz double cream
• 5cm/2in piece fresh ginger , peeled, roughly chopped
• 2 tbsp roughly chopped fresh coriander leaves
• salt
• freshly ground black pepper