For the tahini sauce, mix together all the ingredients with some seasoning in a small bowl.
Warm the flatbread in a dry frying pan – around 30 seconds on each side. Spoon the tahini sauce onto the flatbread and top with the falafel and avocado, then scatter with the herbs, squeeze over the lime juice and add the chilli sauce. Roll up and enjoy.
Want to save time? Use shop-bought hummus instead of the tahini sauce.