Put the crayfish tails into a food processor. Add the egg, yoghurt or soured cream and the dill. Blitz until you get a coarse mixture. Add the zest of the lemon and squeeze in some of its juice. Season with salt and pepper, add the cayenne.
Now add 3 or 4 Tbsp of the chickpea flour. Blitz and add more flour if needed to get a thick but still runny batter.
Heat some oil in a frying pan. Drop about 5 dollops of batter in the pan then, using the base of the spoon, flatten them into circles. Cook for a couple minutes then turn them over. Cook for another minute or so until light brown, then transfer them to a plate.
Repeat with the rest of the batter.
Serve warm or at room temperature with a squeeze of lemon juice.