Black mustard seeds are extremely versatile, and one of the few spices that are commonly used across all regions of India. They really are an unsung hero: widely used, but sadly not often understood. In a lot of Indian dishes they are used as more of a seasoning than a base flavour – they really perk up a lentil or rice dish when fried in a little oil with curry leaves (a match made in heaven). For that reason, mustard seeds are great for healthy eating, when you want to add flavour without adding fat.

In the eastern regions of India, mustard seeds are often paired with fish, a classic combination in Bengali celebratory dishes; in the west of the country, they are used to perk up yoghurt and rice, as well as Gujarati coconut curries. In Rajasthan they provide more of a base flavour for curries. Similarly, in Kashmir and Punjab, lamb is often cooked in mustard oil. Around Hyderabad, Chennai and Madras, they are key to rich, hot curries. As for the south – if there were 1,000 dosa, sambar or lentil recipes, I’d say that mustard seeds feature in 999 of them.

Try frying them in a little oil with a handful of curry leaves, then fold through yoghurt to serve with meats and curries, or stir through rice to add texture and flavour. You can also use them to grow your own mustard cress – just soak them in water overnight, drain, then spread between damp kitchen cloths and leave in a warm place. The seeds will have sprouted within three days, and can be used in salads or as a garnish.

King prawns baked with mustard and coconut

The pungency of a yellow mustard sauce is elevated in flavour and texture by adding fried black mustard seeds.

Serves 4
250ml thick coconut milk
100ml Greek yoghurt
75g yellow mustard seeds (soaked overnight, blended to a paste with 25ml white vinegar)
6 green chillies, slit lengthways
4cm piece ginger, finely sliced
2 tsp salt
1½ tsp sugar
5 garlic cloves, minced
8 large prawns, slit in half, head and shell on, cleaned and dried on a kitchen towel
75ml mustard oil
1 tsp black mustard seeds
50g coriander, finely chopped
1 tsp garam masala

1 Heat the oven to 180C/350F/gas mark 4. Whisk together everything except the prawns, mustard oil, mustard seeds, coriander and garam masala.

2 Heat the mustard oil in a pan to smoking point and let it cool. Reheat the oil and add the mustard seeds. Once the seeds crackle, add the spice mix and bring to the boil, whisking regularly, taking care not to split the mix. Once it has boiled, reduce the heat and simmer for 2-3 minutes.

3 Arrange the prawns on a tray, shell-side down. Pour the sauce over the tails, cover with foil then cook for 18 minutes. Sprinkle with coriander and garam masala, then serve with rice.

Three more ways to use black mustard seeds

• Mung bean and apple salad Mix 100g green mung bean sprouts with 100g soaked split yellow mung beans, 3 diced green apples, salt and lemon juice. Fry 1 tsp mustard seeds with curry leaves in 1 tbsp oil, then stir through the salad.
• Yoghurt rice Mix 100g Greek yoghurt with 70g cooked rice, 1 chopped chilli, 1 tsp fresh ginger, 2 tbsp chopped coriander and a pinch of salt and sugar. Heat 1 tbsp veg oil and add ½ tsp mustard seeds, curry leaves and asafoetida. Add to the rice with a little milk.
• Red lentils Boil 175g red lentils with salt and turmeric for 30 mins. Heat 2 tbsp veg oil, add 1 chopped red chilli, 1 tbsp mustard seeds and 10 curry leaves. Fry till crackling. Add 2 chopped garlic cloves. Fry till golden. Tip into the lentils with some chopped coriander.