Preheat the oven to 150C/300F and place a large cast iron casserole dish on the hob (stove top).
Add 2 tbsp of the oil and heat on a high heat.
Mix the flour with a pinch of salt and pepper, and coat the beef chunks with the flour.
Place the beef in the hot oil and brown (you may need to do this in two batches). Remove from the pan and place the sealed beef in a bowl.
Add the remaining 1 tbsp of oil to the pan and then add in the onion. Turn down the heat and cook slowly for a couple of minutes whilst stirring (scrape up any crispy bits on the pan as you go).
Add in the garlic, ginger and turmeric and cook for another couple of minutes whilst stirring. At this point, you may find that the base of the casserole dish is starting to get quite brown and the onions may be beginning to stick a little. If so, add a splash of cold water to prevent the pan from burning.
Add in the lemongrass, chillies, tamarind paste, ground coriander, pepper, cinnamon, lime leaves, sugar and salt. Mix together and allow to cook for a minute.
Add in the coconut milk and bring to a gentle bubble, stirring to ensure nothing is sticking to the base of the casserole dish.
Add the beef back in and stir. Place a lid on and put in the oven. Cook for 90 minutes – giving the curry a stir after 45 minutes.
After 90 minutes, give everything a stir again and ensure nothing is sticking, then remove the lid and continue to cook in the oven, uncovered for another 2-2.5 hours. Stir very gently every half an hour (to ensure you don’t break up the beef chunks).
Towards the last hour of cooking time, you’ll see that the sauce is going darker and the oil is separating and rising to the top.
If you like a bit of sauce with your rendang then take your rendang out of the oven when there is a bit of oil on top, and is still quite saucy underneath.
If you prefer your rendang drier, then leave to cook for longer. Keep a close eye on it to ensure it doesn’t burn. Stir gently and often. Drain any remaining oil off before serving. Gently stir the rendang, and then serve with rice and sprinkled with strips of spring onion (scallions)
Can I make it ahead?
Yes, make the rendang, then cool and cover. Reheat in the oven at 150c/350F for 30-35 minutes, or until piping hot throughout. Heat the rendang covered for the first 20 minutes, then uncovered for the final 10-15 minutes. You can add a splash of water if the rendang is looking particularly dry, but be careful when stirring it in, as the beef will be very tender, and may fall apart.
Can I freeze it?
Yes, make the rendang, then cool, cover and freeze. Defrost in the refrigerator overnight, then reheat as per the 'Can I make it ahead?' instructions above.
Can I cook it in the slow cooker?
Cooking the recipe in the slow cooker will give you a nicely flavoured curry, BUT you won't get the oil separating from the coconut milk, which means you won't get the sauce reducing or the caramelization of the beef.If you did want to use the slow cooker and you want that dry-caramelized finish, you can make up the curry right up to the part you add the beef back in with the coconut milk. Bring to the boil, then transfer to the slow cooker. Cook on high for 4-5 hours or low for 6-8 hours. After this time, transfer to an ovenproof casserole pan and place in the oven, uncovered at 160C/320F for 1-1 1/2 hours, until the sauce reduces, the oil separates from the coconut milk and the beef caramelizes to a dark golden brown. Stir every 30 minutes during the time cooking in the oven.Nutritional info is per serving for the rendang only (not rice) - after the oil (approx 125ml/half a cup) has been drained off. If you don't drain off the oil, add 180 cals per serving (720 cals extra for all of the rendang)