Add chicken thighs, onions, celery sticks, spring onion greens, ginger, garlic cloves to a chopper or mixer and pulse to get coarse mixture. Add rest of the ingredients - oyster sauce, soy sauce, cornflour, salt, pepper, sesame oil, coriander leaves & pulse once or twice just until it gets mixed well. Transfer to a bowl, make lemon sized meatballs & place on a plate.
250 grams chicken thighs, ¼ cup + 1 tablespoon cubed onions, 2 sticks celery cut into 3 inch pieces, ½ + ⅛ cup roughly chopped spring onion greens, ¾ inch ginger, 4-5 garlic cloves, 1 tablespoon oyster sauce, 1 teaspoon soy sauce, 1 teaspoon cornflour, ¼ teaspoon salt, ½ teaspoon pepper, 1 tablespoon sesame oil, 3 tablespoons finely chopped coriander leaves