Heat half the oil in a large pan. Put the chicken in a large bowl, season well and toss through the cornflour, then cook in batches until browned all over (don’t overcrowd the pan or the chicken won’t brown). Tip each batch straight into the slow cooker as you go, adding a little more oil to the pan if you need to. Add the onion, garlic and peppers, cook for a few mins to just soften, then add these to the slow cooker too. If there is any cornflour remaining in the bowl, add a drop of the coconut milk and swirl it around, then pour into the slow cooker. Add the remaining coconut milk, the soy sauce, vinegar, sugar and bay leaves, season with plenty of black pepper, then heat the slow cooker to Low, cover with the lid and cook for 5-6 hrs until the meat is tender and the sauce has thickened. (If you don’t have a slow cooker, tip the ingredients back into the pan, cover and cook for 11/2-2 hrs, stirring every now and then to prevent it from catching, and adding a splash of water if the stew looks dry.) If the sauce in the slow cooker is too thin, thicken it with the remaining cornflour. Mix 1-2 tsp cornflour with 1-2 tsp cold water to make a paste, ladle 2-3 spoonfuls of the sauce into a saucepan and bring to says a simmer, then stir in the cornflour paste and cook for 1-2 mins to thicken. Stir back into the slow cooker and cook on High for 10 mins more. Serve with rice and stir-fried veg.