Trim the courgettes. Roughly chop them. Pop them in a food processor. Blitz a few times to make ‘rice’. No processor? Just coarsely grate them. Put the ‘grains’ in a bowl. Put to one side.
Peel the garlic, ginger and shallots. Roughly chop them. Remove the tough outer layer from the lemon grass, then chop. Roughly chop the chilli (remove the seeds and white bits for less heat or leave it out if you prefer a mild curry).
Add the garlic, ginger, shallots, lemon grass, chilli and coriander stalks (save the leaves for later) to the food processor. Blitz to a rough paste. No fancy kit? Grate or finely chop ingredients.
Warm 2 tsp sunflower oil in a deep frying pan or wok. Slice the steaks into thin strips. Add to the pan. Stir for 2-3 mins or till browned. Set the steak aside on a plate. Add the chilli paste to the pan. Fry for 3 mins till it smells aromatic and spicy.
Stir in the sachet of tamarind paste. Add 200ml boiling water. Cover. Simmer for 10 mins till the sauce thickens a little.
Stir the steak strips into the sauce. Simmer for 4-5 mins till just cooked through. Measure out 2 tbsp of the coconut milk. Add to the curry. Season to taste.
Meanwhile, heat a separate frying pan or wok. Stir fry the courgette rice with 2 tbsp cold water for 1-2 mins till tender with a little bite. Serve the curry with the rice, sprinkled with the coriander leaves.