TIP: The only tricky thing about falafel is that you have to soak the chickpeas well in advance. Never use tinned chickpeas to save time, because your falafel will fall apart as you fry them. Good falafel batter is too moist to easily roll into balls, so use falafel tongs if you have them. If not, you can make quenelles of the batter using two dessert spoons.
- Soak the chickpeas in plenty of cold water for 12 hours. Drain and blend to a fine – but not completely smooth – puree in a food processor. Transfer to a large bowl and set aside.
- Puree the remaining ingredients (except the water and oil) and add the mixture to the chickpeas. Gradually pour in about 100ml of cold water and knead the mixture until smooth.
- Preheat the oven to 100°C. Heat the oil to 180°C in a deep-fryer or otherwise in a large, heavy-based saucepan. Fry a test falafel first. Fill the falafel tongs with batter, smooth the top with a kitchen knife and lower it into the hot oil (or, make a quenelle of batter using two dessert spoons and lower it into the oil). Fry for 4–5 minutes, until lightly browned all over. Remove from the oil and, when cool enough to handle, taste. Add more salt or water to the remaining batter as necessary.
- Fry the falafel balls in batches until golden brown. Remove from the oil and set aside to drain on a plate lined with paper towel. Keep warm in the oven while you make the rest.
- To make the tahini sauce, use a handheld blender to mix the tahini with the lemon juice and garlic (if using). It will start to stiffen. Keep blending and gradually add a few drops of water at a time, until the sauce has the consistency of a salad dressing. Season to taste with salt.
- Toast the pitas until hot but still soft. Cut each open and spread the inside with tahini sauce. Fill each with some falafel balls and Israeli salad.