10 fresh red finger-length chillies
1½ tsp coriander seeds
½ tsp cumin seeds
½ tsp caraway seeds
3 garlic cloves, roughly chopped
½ tsp flaked sea salt
2 tsp tomato purée
2½ tsp lemon juice
1 tbsp light olive oil (not extra virgin, as it will flavour the harissa too heavily)
7 drops rose water (optional)
Place a frying pan over a medium heat. Char the chillies, turning them now and then for 10 mins, until fairly blackened all over. Allow to cool. In a small frying pan, gently toast the coriander, cumin and caraway seeds, swirling them often for about 2 mins, until fragrant. Peel away the skins from the chillies, chop off the stalk and deseed them.
With a pestle and mortar (or a spice grinder), pound the chillies, seeds, garlic and salt together, making as fine a paste as possible. Stir in the tomato purée, lemon juice, oil and rose water, if using. Allow the flavours to combine for 1 hr before using.