Chop the chicken into bite sized strips. I find it's easier to chop if it's slightly frozen. The original recipe said to mince it in the food processor, that sounded un-pleasant to me. I don't like mushy chicken paste. Mix chicken with soy sauce, wine, cornstarch, sugar, pepper and set it aside to marinate.
Meanwhile, rinse mizuna and chop the stems and leaves.
Heat 2 tsp of oil in a wok or skillet over medium high heat. Add the chicken and stir fry until it is fully cooked through. When the chicken is fully cooked and add the mizuna. Toss the mizuna in the hot pan with the chicken and it will start to wilt and cook down, season to taste with salt.
Serve with rice. I use brown rice. John added additional soy sauce and kosher salt to his. Connor ate 3 pieces of the chicken and at least a teaspoon of rice.