Drain and pat the soaked broad beans dry, then pulse them in a food processor with the spring onion, garlic, and plenty of curly parsley until the mixture is coarse rather than smooth.
Add the cumin, salt, pepper, and baking soda, then refrigerate the mixture for at least one hour.
Shape into falafel and fry in hot vegetable oil until golden and crispy.
Meanwhile, prepare the yogurt sauce by mixing together the Greek yogurt, lime juice and zest, olive oil, salt, pepper, and finely chopped Mioorto chives.
Serve the falafel with the yogurt sauce and a sprinkle of fresh curly parsley.
