Soak the chickpeas in plenty of water with the baking soda overnight in the fridge, or ideally 24 hours.
Strain and rinse the chickpeas very well.
Lightly toast the cumin seeds, coriander seeds and black peppercorns until fragrant. Blitz in a spice grinder or mortar and pestle. (Otherwise you can use pre-ground coriander, cumin and black pepper)
Add the chickpeas, washed herbs, onion, chili, garlic to blender and blend until smooth.
Transfer to a mixing bowl and stir in the spices and salt.
Allow this mix to rest at least an hour or ideally - overnight.
Before cooking: Add the lemon zest to freshen up the the mix, add baking powder for fluffiness and mix everything very well.
To shape falafels
Form falafel mixture into round balls or slider-shaped patties using wet hands or a falafel scoop. I usually use about 2 tablespoon of mixture per falafel. You can make them smaller or larger depending on your personal preference.
The falafel balls will stick together loosely at first, but will bind nicely once they begin to fry.
Heat the oil in a pan or deep fat fryer to 190 C / 375 F
Deep fry the falafels in batches and cook until golden brown on the outside - approx 3 minutes.