Soak the Chickpeas overnight. You should get around 2-1/2 cups of soaked chickpeas. Refer Tip 1 for adjustments with respect to Zucchini-Chickpeas ratio.
Grate the Zucchini - will make about 1 cup.
Add about 1 tsp salt to Zucchini and place it in a colander. Set aside for 30 minutes.
Using a cheesecloth or hands, squeeze out as much water as you can. Trust me, you won't believe the amount of water that comes out!
Meanwhile drain the chickpeas well.
Add it along with rest of the ingredients in the "Falafels" section except sesame seeds in a food processor.
Do not add water. You will have to stir the mixture now and then to be able to grind it into a paste. The moisture from the herbs, onion and some from zucchini should be enough. Pulse it now and then
until it comes together into a coarse paste. Adjust seasoning and add the sesame seeds. Stir to combine.
Make small patties. The mixture will be soft but with enough binding to be able to form patties. If you are not able to, you can refrigerate this mixture for 30 minutes and try again. If that's hard (which I suspect should not be the case for this recipe), you can add some flour to it.
Heat some oil in a cast iron pan and place the patties in med-high flame.
Cook until browned and turn the other side.
Prepare the rest of the patties in the same way. You can keep these warm in a 200F oven.
Meanwhile prepare the sauce. Add all the ingredients for the sauce together.
Give it a good whisk until well combined. Add water if required. Adjust seasoning to taste. Set aside.