Pour the chickpeas into a large bowl and cover them by about 3 inches of cold water. Let them soak overnight. They will double in size as they soak – you will have between 4 and 5 cups of beans after soaking.
Drain and rinse the garbanzo beans well. Pour them into your food processor along with the chopped onion, garlic cloves, kale, flour, salt, cumin, ground coriander, black pepper, cayenne pepper, green chilies and cardamom.
Fill a skillet with vegetable oil to a depth of 1 ½ inches. I prefer to use cooking oil with a high smoke point, like grape seed or peanut oil. Heat the oil slowly over medium heat. Meanwhile, form falafel mixture into round balls or slider-shaped patties using wet hands or a falafel scoop. I usually use about 2 tbsp. of mixture per falafel. But size could be varied depending on your personal preference. The balls will stick together loosely at the beginning, but will bind nicely once they begin to fry.
Note: if the balls won't hold together, place the mixture back in the processor again and continue processing to make it more paste-like and add 1-2 eggs to the mix