Heat some oil in a wok or heavy-based frying pan and stir-fry the curry paste for about 2 minutes until it releases its fragrance.
Add the beef or buffalo and stir-fry for 5–6 minutes.
Add three-quarters of the coconut milk, the sugar, tamarind paste and fish sauce, reduce the heat and simmer gently for 5–6 minutes. If the mixture is looking too dry, add