1. Firstly make the sauce in a food processor. Pour in the coconut milk, tomato puree, garlic, ginger, chilli, fish sauce and lime juice.
2. Cut the greens off the spring onions and finely slice them. Keep them aside for garnish. Add the white tops to the processor. In a pestle and mortar grind together the coriander seeds and cumin seeds. Add these to the sauce.
3. Sprinkle in the turmeric, chilli powder and sugar.
4. Blitz to a smooth sauce before pouring into a pan.
5. Add the cinnamon stick and 2 kaffir lime leaves. Finely slice the 3rd one and keep aside for garnish.
6. Bring the sauce to the boil, then reduce and allow to simmer for 10 minutes.
7. Stir in the beef and cook for a few more minutes before removing from the heat. Taste and adjust the seasoning with more lime juice, fish sauce, sugar and chillies if you need to.
8. Serve the spicy coconut curry with some simple steamed rice, garnished with the spring onion greens, shredded lime leaves, fresh red chillies and basil.