1. For the rasam, add the first four ingredients, 1.2 litres of water and 1 teaspoon of salt to a medium saucepan on a medium-high heat. Bring to the boil, then lower the heat to medium and simmer gently for 20 minutes, stirring to break apart the tamarind pulp. Strain through a sieve into a bowl, pushing down to extract as much flavour as possible. Discard the aromatics.

2. Meanwhile, put the rice into a medium saucepan, for which you have a lid, along with 220ml of water and ¾ teaspoon of salt. Bring to the boil on a medium-high heat, then lower the heat to medium-low and cover loosely with the lid, leaving a small gap for some steam to escape. Cook for 20 minutes, then remove from the heat and let sit, uncovered, until cool.

3. Toss the tomatoes in 1½ teaspoons of oil. Place a large sauté pan on a high heat. Once smoking, add the tomatoes and cook, tossing occasionally, until charred and blistered, about 4 minutes. Set aside. Add the lemons and cook until charred, 30–50 seconds per side, then set aside. Turn the heat down to medium-high, add the remaining 2 tablespoons of oil, the cumin and mustard seeds, dried chillies, curry leaves (if using) and garlic and cook for 90 seconds, until fragrant. Add the grated tomatoes and cook for 5 minutes more, then add the sugar, tamarind liquid, charred tomatoes and ½ teaspoon of salt. Bring back up to the boil and simmer for 8 minutes. Set aside while you prepare the rice balls.

4. For the rice balls, put the oil into a sauté pan on a medium-high heat. Add the onion and cook for 7 minutes, until softened and browned. Add the garlic and ginger and cook for 90 seconds. Remove from the heat and transfer to a bowl with the cooked rice, coriander and spring onion. Mix well. With lightly oiled hands, form into twelve balls, weighing 30–35g each. 5. To serve, return the pan of rasam to a medium-high heat to heat through, then add the charred lemon slices and the sticky rice balls. Top with the picked coriander and serve.