Green tomatillo salsa (Salsa verde)

1. Remove the papery husks from the tomatillos and wash off their sticky coating in lukewarm water.

2. Put the tomatillos and serranos in a saucepan with enough water to cover and cook for 8-10 minutes until the tomatillos turn olive green and soften, but don't burst.

3. Lift them out with a slotted spoon; keep a little of the cooking water.

4. Put the tomatillos, serranos, a quarter of the onion, the garlic, the coriander and salt in a blender and blend briefly – it can keep a little texture. If it's too thick, thin it with a little cooking water.

5. Taste and round it off with salt and, if needed, a pinch of sugar – tomatillos can be very sour.

6. Serve cold or lukewarm with tacos, enchiladas or chilaquiles; it keeps for 4-5 days in the fridge.

Tip: For a smokier flavour, char the tomatillos, chilies and onion in a dry pan instead of boiling them – that turns it into salsa verde asada.