Add the chickpeas, lentils, breadcrumbs, coriander, lemon zest, paprika, coriander, and cumin to a food processor. Season with salt & pepper, then pulse until it is well mixed but still has some texture.
Divide the mixture into four, then shape into flat disks. Dip each patty into the sesame seeds and press lightly so that it sticks as much as possible.
Heat the oil in ’n frying pan, then fry the patties 2 at a time until they are golden on both sides. Set aside.
Slice the hamburger rolls open horizontally and give them a quick toast in the still-oiled frying pan.
Mix the mayonnaise and relish together in a small bowl. Set aside.
To assemble: Arrange some lettuce on the burger bun bottom halves, then top with tomato, the veggie patty, the sauce and sliced chillies (optional).