Step 1 Place fava beans in a bowl and cover with plenty of cold water. Soak for 2 days, changing the water daily (in hot weather change the water twice daily).

Step 2 Soak chickpeas on the second day in a separate bowl in plenty of cold water.

Step 3 Drain beans and chickpeas and rinse under cold running water; drain again. Remove the skins from the fava beans and discard them. Do not skip that step or the falafel will not taste good.

Step 4 Combine fava beans, chickpeas, onion, garlic, and parsley leaves in the bowl of a food processor; pulse until pureed, scraping the sides often to ensure everything is evenly processed to a smooth paste. Add cayenne pepper, coriander, cumin, baking soda, salt, and pepper. Transfer to a bowl; cover and let mixture rest for 30 minutes.

Step 5 Line a baking sheet or a large tray with waxed paper.

Step 6 Shape the mixture into 25 to 30 evenly sized patties and place them on the prepared baking sheet, leaving at least 1/2 inch between them. Let rest, uncovered, for 30 minutes.

Step 7 Preheat the oven to 350 degrees F (175 degrees C).

Step 8 Pour oil into the bottom of a large skillet until it just covers the bottom. Heat until oil is hot enough to sizzle a breadcrumb.

Step 9 Carefully lift the falafel from the waxed paper using a spatula. Fry a few falafel at a time and do not overcrowd the skillet. Fry until crisp and brown on the underside, 3 to 5 minutes. Flip, and fry on the other side until browned, another 3 to 5 minutes. Remove from skillet and transfer to a baking sheet. Place the finished falafel in the preheated oven to keep warm while you fry the rest, adding more oil to the pan as needed.