In a food processor, whizz the onion, garlic and chillies (seeds removed if you prefer a milder curry) until they form a paste.
Heat the oil in a large saucepan and add the onion mixture. Gently fry for a couple of minutes. Add the yogurt, turmeric, chilli and ground coriander seeds, and fry for a further 2 minutes.
Add the beef and fry until it is coated with the onion/spice mixture and browned. Add the coconut milk, bring to the boil and then turn the heat down to a simmer. Simmer for 1½-2 hours, stirring from time to time. As the curry cooks, the sauce will reduce and thicken, and it is ready when there is just enough sauce left in the pan to coat the meat.
Add the garam masala and chopped fresh coriander. Season with salt to taste and serve.
*Inspired by Lynda H. featured in the Realfood Cookbook
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.