Preparation time: 20 mins plus overnight soaking
Cooking time: 20 mins

225g/8oz dried chickpeas, soaked overnight in water
1 tbsp tahini
1 tsp salt
1 tsp baking powder
1 tsp cumin seeds
1 tsp ground coriander
1/2 tsp cayenne pepper
1 garlic clove, crushed
100g bag watercress, roughly chopped
juice half a lemon
2 tbsp vegetable oil, for frying
To finish:
100g bag watercress
150g Greek style yogurt
1 small clove garlic, crushed
4 wholemeal pitta bread

Drain the chickpeas and place in a food processor with the tahini, salt, baking powder, cumin, coriander, cayenne, garlic, watercress and lemon juice. Whizz until very finely chopped but not puréed. (If you have time, set the mixture aside for a couple of hours, so the flavours can mingle, but it's not imperative).

Preheat the oven to 220C/Fan 200C/Gas Mark 6. Place a large roasting tin in the oven to heat up. Using a wet hand shape the mixture into 16 balls, then flatten slightly into patties.

Add the oil to the roasting tin, return to the oven for 2 mins, then carefully add the falafel, tossing to coat in hot oil. Bake for 20 mins, turning once until crisp and golden.

Whilst they cook, roughly chop half the remaining watercress and stir it into the yogurt with the garlic and seasoning to taste. Lightly toast the pittas on each side, cut each in half and open up each half to make a pocket. Fill the pitta pockets with falafel, remaining watercress and the yogurt sauce. Serve whilst warm.

Cook's tip

Tahini is a sesame seed paste used widely in Middle Eastern cookery. It adds a savoury, nutty flavour to these falafel and is available from health food stores and large supermarkets.