Tip the rice into a bowl. Cover with cold water. Whisk for 2 mins (you can use a fork) till the water goes cloudy. Drain the rice, rinse and tip into a small pan. Pour in 300ml boiling water. Add a pinch of salt. Cover, bring to the boil and then turn down the heat, gently simmer for 25 mins so the rice absorbs the water. Take the pan off the heat and leave the rice in it, covered, to steam and keep warm.
While the rice is cooking, peel and finely chop the onion. Dice the tomatoes. Peel and grate the garlic and ginger. Finely slice the chilli, flicking out the seeds and white bits for less heat.
Put a pan on a medium heat for 1 min. Add ½ tbsp oil and the onion. Season with a pinch of salt. Cook and stir for 5 mins till the onion has softened a little. Stir in the tomatoes, garlic, ginger and chilli. Add 1 tsp each turmeric and black mustard seeds. Add 6 curry leaves.
Give everything a good stir and cook for 2 mins till the pan smells aromatic. Pour in the coconut milk. Add 250ml boiling water. Cover and bring to the boil. Simmer for 5 mins to mingle the flavours.
Add the fish pie mix to the pan. Cover and simmer for 5-8 mins till the fish is opaque and flakes easily when pressed with a fork. Taste the curry and add a pinch more salt if you think it needs it.
Fluff the rice up with a fork. Spoon into 2 warm bowls. Top with the curry and serve.