Place the chicken in a slow cooker. Mix together the soy sauce, rice vinegar, ginger, garlic and honey and place in the slow cooker. Pour in roughly 100ml water so that the chicken is three-quarters submerged in the liquid. Place on a high heat and cook for 2-3 hours, until the chicken is very tender and falling apart.
Towards the end of the chicken cooking time, cook the rice according to the instructions on the packet.
Remove the chicken from the slow cooker and place the sauce from it in a saucepan. Mix the cornflour with 2 tbsp water and mix until smooth. Add this to the sauce and bring to the boil. Simmer for 3 minutes until thickened. Shred the chicken.
Heat a wok and mist with spray oil. Add the garlic, ginger and chilli and cook for 1 minute. Add the pak choi and cook for 1 minute, then add a splash of water and cook for a further 1 minute, until just softened. Add the shredded chicken back to the pan with the sauce to heat through. Serve the chicken and vegetables on the rice sprinkled with sliced spring onion and sesame seeds.