Use a small paring knife to cut the berries in half and use the pointed end to flick out the small seed. Set the berries aside.
Heat a medium saucepan on medium-low heat, then add the olive oil and onion. Cook the onion gently until soft, then add the berries and stir occasionally while cooking for 5 - 8 minutes.
Add the sultanas, coconut sugar, cinnamon, allspice, salt and chilli, and stir through the berry mixture..
Add the vinegar and increase the heat to bring the whole mixture to a simmer
Simmer for 30 - 35 minutes until the liquid has reduced and you have a thick chutney. Adjust the seasonings and sweetness if needed.
Spoon hot into a sterilised jar and seal. Once cooled, store in the fridge for up to 8 weeks.
