Spiced green mango sauce (Amba)

1. Peel the green mangoes, cut the flesh off the stone and cut into small cubes or thin strips.

2. Toss with the salt and turmeric, cover and set aside for 2-3 hours (or overnight) so they release their juice.

3. Heat the oil in a pan and add the mustard seeds; when they start to pop, add the fenugreek seeds and crushed garlic and fry for half a minute.

4. Add the mango with its juice, the chilli powder, sugar and water and simmer over low heat, stirring occasionally, for 20-25 minutes until the mango is soft.

5. Blend partly or completely with a stick blender, then season with lemon juice; if too thick, thin with a little water.

6. Pour into a clean jar, let cool and keep in the fridge.

Tip: Amba travelled from India to the Middle East with Iraqi Jews and is now the essential tangy, slightly bitter sauce of sabich and shawarma. The strong fenugreek aroma is characteristic; if you can't find green mango, choose the hardest, least ripe mango and add more lemon.