For a deeper flavour, if you have time, heat the oil in a frying pan over a medium heat and fry the onion for 6-8 mins until softened. Add the chicken and fry for a few minutes until seared all over (but not cooked through), then add the garlic and ginger and cook for 2 mins until fragrant. Stir in the curry paste and cook for 1 min.

Tip into your slow cooker along with the coconut milk, tomatoes and sweet potato or butternut squash. Alternatively, put everything but the oil, coriander and chilli in your slow cooker and stir to combine. Cook on high for 5 hrs or low for 8 hrs, until the chicken is tender and cooked through. Remove the lid for the final 1 hr to thicken the sauce. Serve over rice or with naan bread with a scattering of coriander and red chilli, if you like.