Soak the dried chickpeas; rinse them and then put them in a large bowl, cover with lots of cold water and soak for 12 hours, or overnight. Drain and rinse them, and then measure out 2 & 1/2 cups, you will have some leftover chickpeas.
In a food processor add the onion and garlic cloves, pulse a couple of time and then add the serrano as well.
Stop the machine, scrape down the side and add in the fresh parsley and cilantro. Firmly pack the herbs in the cups. Process the herbs until finely minced, stop and scrape down the bowl as necessary while pulsing the food processor.
Add the drained chickpeas to the food processor and pulse until they start to break down. Scrape down the sides, and process until the mixture is even and finely ground, but not pasty or liquidly. The mixture should hold together when you press it between your fingers.
Remove the mixture to a bowl andadd the salt, baking soda, flour, cumin, ground coriander, lemon zest and juice. Add the flour if your mixture seems excessively wet. Make sure it is well combined, but don't compact the mixture.
Heat your oil in a deep pot. Scoop out 1&½ tbsp of the mixture and roll between your palms to form into round balls. Set aside on a plate until you have no more mixture left. Slowly add the falafel into the oil. Work in batches so you don't crowd your pan. Fry the falafel for about 4 to 5 minutes, until they are a nice deep brown. Drain on paper towel and serve.
FOR AIR FRYING: pre heat the airfryer at 400°F for 5-7 min. Place the falafel in the air fryer, make sure not to over crowd, spray them with cooking oil and air fry for 7-10 mins until golden brown. *pro tip, spray the air fryer basket as well with some cooking oil so the falafel does not stick.
Serve in a pita with sliced red onions, carrots and cucumbers! Don't forget to add the white sauce! Enjoy!