Heat oven to 200C/180C fan/gas 6, then roast the peanuts on a baking tray for 5 mins until golden brown. When cool enough to handle, roughly chop. Reduce oven to 180C/160C fan/gas 4.
Heat 2 tbsp coconut milk (use the cream on top if there is any) in a large casserole dish with a lid. Add the curry paste and fry for 1 min, then stir in the beef and fry until well coated and sealed.
Stir in the rest of the coconut with half a can of water, the potatoes, onion, lime leaves, cinnamon, tamarind, sugar, fish sauce and most of the peanuts. Bring to a simmer, then cover and cook for 2 hrs in the oven until the beef is tender.
Sprinkle with sliced chilli and the remaining peanuts, then serve straight from the dish with jasmine rice.
