Start by grating the zucchini, and squeeze out the liquid - I do this by first squeezing the zucchini shreds with my hands and wringing out then liquid, then I press three pieces of paper over the zucchini and squeeze out the remaining liquid.
Place zucchini shreds, garbanzo beans, parsley, bread crumbs, flour, garlic, egg, salt, pepper, and cayenne pepper in a food processor. Process on low for 10 seconds, then scrape the sides of the food processor down and process again for 15-30 seconds until no more whole garbanzo beans remain. Form 4 patties (I like to do this using a biscuit cutter as a mold, but you could just form four patties with your hands.
In a large skillet over high heat, heat 1 tablespoon on olive oil for 1 minute, then add in 4 veggie burger patties. Cook for 6 minutes, then flip and cook for another 6 minutes. Turn heat off, and let veggie burgers sit in the pan for 4-5 minutes as you make the whipped feta and assemble the burgers
For the whipped feta, add the feta, olive oil and water into a food processor and process until smooth, about 1 minute.
To assemble the burgers smear whipped feta on the top of the burger buns.
Spread harissa on the bottom burger buns. Layer lettuce, cucumbers, and roasted red peppers onto the bottom burger bun, place a chickpea and zucchini burger pattie on top of the veggies and then place top bun on the burger, press down and enjoy.