Homemade green curry paste (Phrik kaeng khiao wan)

1. Toast the coriander seeds and cumin in a dry frying pan for 1-2 minutes until fragrant, then grind finely in a mortar with the white pepper and salt.

2. Roughly chop the green chillies; thinly slice the soft lower part of the lemongrass and the galangal, and shred the lime leaves very finely.

3. Roughly chop the shallots and garlic; use the coriander stems and – if you have them – the roots, finely chopped.

4. In the mortar, first pound the toughest ingredients – lemongrass, galangal and lime leaves – to a pulp, then gradually add the chillies, coriander, shallots and garlic.

5. Finally work in the shrimp paste and ground spices and pound until you have a smooth, thick paste; you can also use a food processor with a splash of water.

6. Spoon into a jar and cover the surface with a little oil; it keeps for 1 week in the fridge or 3 months in the freezer.

Tip: The soul of Thai green curry: homemade paste is fresher, more fragrant and brighter in colour than shop-bought. This amount makes one curry for 4; control the heat by removing some of the chilli seeds.