Step One First make the mustard spice mix. Put all the spices in a medium, cast-iron frying pan and set over medium heat. Stir and fry until the spices are just a shade darker and emit a roasted aroma. Empty the spices into a bowl or on to kitchen paper and allow to cool. Then put them into a clean coffee grinder or other spice grinder and grind as finely as possible. These quantities make more than you need for this recipe but you can store the spice mix in a tightly lidded jar, away from sunlight and moisture, for use in other recipes.

Step Two Rub the pork cubes well with the ginger, garlic, salt and turmeric. Cover and set aside for 30 minutes, or up to 8 hours if desired, refrigerating if necessary.

Step Three Pour the oil into a large, preferably non-stick, lidded pan and set over a medium–high heat. When the oil is hot, put in the whole mustard seeds. As soon as they pop, which will be in a matter of seconds, add the curry leaves and, a second later, the pork, together with its marinade. Stir for a minute. Cover, reduce the heat to medium, and let the meat cook for the next 5 minutes, stirring now and then and replacing the cover each time. The meat should brown lightly. Add 5 teaspoons of the mustard spice mix and stir for a minute. Add the tomatoes and cook, stirring, until the tomatoes turn pulpy, about 2 minutes. Now add 250ml (8fl oz) water, stir, and bring to the boil. Cover, reduce the heat, and cook very gently, lifting the lid occasionally to stir the contents, for 50–60 minutes or until the meat is tender. Check for salt before serving.