Drain the beans, then mash them roughly with a potato-masher or fork.
Add the shallot, garlic, courgette, lemon yest, parsley and salt and pepper. Combine well.
Add half of the chickpea flour, and mix with your hand. Add more flour until you get a dough-like, sticky mixture.
Make 4 balls and flatten these between your palms. Put them on a tray, lined with baking paper. If you have time, chill for an hour.
Preheat the oven to 200°C or set it to grill.
Cut the red pepper into 4 pieces and put them around the patties or onto another tray.
Spray the patties & red pepper pieces with oil, then put the tray in the oven. When they look brown and crispy, turn them over and grill or bake until that side look done too.
Meanwhile toast the buns and prepare the toppings, fillings and condiments to your liking.
Serve the patties and roasted pepper (if used) in the bun with the toppings, condiments and fillings of your choice.