Starting 24 hours before you’re going to make the falafel (a.k.a. the evening before), put the chickpeas in a medium bowl and cover with boiling water. Stir in 2 tablespoons of lemon juice. Cover lightly and let sit at room temperature for 12 hours. The next morning, drain the chickpeas and cover again with boiling water and the remaining 2 tablespoons of lemon juice. Let sit at room temperature until dinnertime. Drain and rinse the chickpeas before proceeding.
In a food processor with the blade running, add the garlic cloves and chop. Add the parsley and cilantro and finely chop. Add the chickpeas and remaining ingredients except Tahini Yogurt Sauce and oil. Process to a smooth puree, scraping down the sides as needed (this will take about 5 minutes—just let the machine rip). Spread the mixture out in a 8- or 9-inch baking dish (this will help it cool faster); cover and freeze 20 minutes, or up to 1 hour. While the mixture freezes, make the Tahini Yogurt Sauce (see below).
Cut the falafel into 16 squares (this is just to help you portion it evenly). Using your hands, shape the mixture into 16 patties, about 2 ½ inches wide (the mixture will be quite soft but should hold together without a problem). Place the patties on a parchment- or wax-paper lined baking sheet. If you have the time, cover the patties with plastic wrap and pop them in the freezer for 5-10 minutes (to help them to keep their shape when cooking). If you’re baking the falafel, preheat the oven to 450˚F with a rack in the upper third. Do Ahead: The patties can be covered with plastic wrap and refrigerated for up to 2 hours.
To Fry: Pour 1 inch of oil into a large, heavy saucepan, preferably enameled cast iron. Heat oil over medium-high until the oil shimmers (when you toss a crumb in it should start to bubble and float back up to the surface). Add a few of the patties, making sure not to overcrowd the pot. Cook 4-5 minutes, flipping the patties one or twice (a fish spatula works great for this), or until evenly golden brown all over. Using a slotted spoon or spider, transfer the falafel to a paper-towel lined baking sheet. Cook the rest of the patties, adjusting the heat as necessary to maintain the oil temperature. To Bake: Line a baking sheet with aluminum foil, and rub it generously with oil (don’t skimp on the oil, this is what will give the falafel their crust). Place the baking sheet in the oven (on top third rack) for 1-2 minutes to preheat. Remove pan from oven, and carefully place patties on top. Brush tops of patties with more oil. Bake 7-10 minutes, or until golden brown on the bottom. Flip the patties and cook an additional 5-6 minutes, or until golden brown on the other side. Transfer to a paper towel-lined baking sheet. Do Ahead: The falafel—baked or fried—can be made up to 30 minutes in advance. Line on baking sheet and place in a 200˚F oven to keep warm.
Serve the warm falafel drizzled with the Tahini Yogurt Sauce. I prefer the falafel either over a lemony salad or stuffed in pita bread with shredded lettuce.