Use a pestle and mortar or a small blender to pound or blend the garlic and the coriander roots and stalks into a paste. Add the prawns, pepper, salt and egg and mix together.
Spread the prawn paste thickly on one side of each piece of dry bread. Sprinkle with sesame seeds and press down firmly.
Heat 5 cm (2 inches) of oil in a wok over a medium heat. The oil is ready when a small piece of bread sizzles when dropped in. (It is important not to have the oil too hot or the bread will cook too quickly and turn brown.) Deep-fry a few pieces at a time, paste-side down, for 3–4 minutes or until golden brown. Lift out with a slotted spoon and place them paste side up on kitchen paper.
Serve hot or warm as a starter with Sweet Chilli Sauce (see