1. Roughly chop half the red onion and place into a food processor with half the shredded carrot, minced turkey, oats and lemon zest. Season with salt and freshly ground black pepper and whiz to a well combined mixture. Using wet hands shape into 20 equal sized balls. Chill until ready to use.
2. Thinly slice the remaining onion. Heat the oil in a large non-stick frying pan and fry the onion and meatballs for 10 minutes shaking the pan occasionally and turning the meatballs frequently until the onion has softened and the meatballs are evenly browned.
3. Meanwhile, shred the white bulbous part of the pak choi and the leaves and set aside separately.
4. In a small bowl mix together the Mirin, soy sauce, lemon juice and caster sugar. Pour over the meatballs and bring to the boil, turn down the heat, scatter over the white bulbous part of the pak choi and simmer for 2-3 minutes.
5. Scatter over the green pak choi and remaining carrot and cook for 2-3 minutes stirring until the pak choi has wilted.
6. Sprinkle over the sesame seeds and red chilli if using. Serve with plain steamed rice.

Cook's tip

Mirin is a sweetened sake or rice wine with a light syrupy texture used a lot in Japanese cooking. It is now readily available in large supermarkets and is a very handy ingredient to keep in your store cupboard. It can be replaced by wine or if you want a kick use sweet chilli sauce and omit the caster sugar (not authentic teriyaki but still very tasty!)