Tip the rice into a bowl, cover with cold water and whisk for 1-2 mins till the water goes cloudy. Drain, rinse and tip into a small pan. Add 300ml boiling water and a pinch of salt. Pop on a lid, bring to the boil then turn the heat down very low. Gently simmer for 25 mins till all the water is absorbed, then take off the heat and leave to steam in the pan, lid on. The rice will stay warm in the pan.
Use a sharp knife to cut the beef stir-fry strips into bite-size pieces. Peel and finely slice the onions. Chop the tomatoes into small pieces.
Peel and grate the garlic and ginger. Halve the red chilli, flicking out the seeds and pith for less heat, and finely chop it. Slide into a mortar and add 1 tbsp tamarind paste and a good pinch of salt and pepper. Bash with the pestle till everything is combined into a paste. No mortar and pestle? See our tip at the end.
Set a large pan or wok over a high heat and warm for 2 mins. Pour in 1 tbsp olive oil and carefully add the beef stir-fry strips. Fry for 2 mins on each side till well browned. Transfer to a plate, and lower the heat to medium-low.
Slide in the onions and cook for 3-4 mins till soft and golden. Stir in the garlic, chilli and ginger and continue to cook for a further 2 mins.
Return the beef to the pan along with the chopped tomatoes, 1 tbsp peanut butter and the coconut milk. Bring to the boil, then cover and reduce the heat to a simmer. Cook for 20 mins.
Fluff up the cooked rice with a fork and pile into bowls. Spoon the rich tamarind and coconut beef curry over the top and serve.