Pulse onion, cilantro, parsley, and 1½ tsp. salt in a food processor until finely chopped. Transfer to a vast kitchen towel. Gather ends of towel in any palm and turn over sink, wringing out as most glass as possible. Mix onion mixture, piquancy mixture, egg yolk, paprika, black pepper, cayenne, and remaining 1 tsp. salt in a vast play to combine. Gently overlay lamb into piquancy reduction to uniformly discharge (be clever not to overmix). Using a 1-oz. ice cream dip or soppy hands, form beef reduction into 1½” balls (you should have 16).