In the slow cooker, whisk together the coconut milk, peanut butter, chicken stock, honey, soy sauce, sriracha, curry powder and lime juice until well-blended.
In a medium-sized mixing bowl, coat the diced chicken in the seasoning. Add a drizzle of oil to a large pan over medium-high heat and once hot, space out the chicken. Fry for a few minutes on each side to build up a nice crust (important to lock in the seasoning and develop flavour). Place in the slow cooker, leaving any excess oil/fat behind (chicken doesn't need to be cooked through at this point).
Top the pan up with oil if needed, then add the onion, garlic and ginger. Sweat it all down until soft and golden, then scrape into the slow cooker (be careful the garlic/ginger doesn't burn).
Give everything a mix, then pop on the lid and cook on HIGH for 3 hours or LOW for 6 hours. Mix in the green beans, red pepper and water chestnuts, then cook for a further 30 minutes for HIGH or 1 hour for LOW, or until the veg has softened. The consistency should be perfect at this point, but if it's looking a little watery, just leave the lid off the reduce. Check for seasoning and adjust with salt or soy sauce if you think it needs it.
Serve with rice and/or flatbreads with crushed peanuts on top (optional).