1 lemongrass, roughly chopped
1 piece pared lime zest
1 large pineapple, peeled and cut into thick slices
200g/7oz demerara sugar
few star anise, broken up
50驳/1戮辞锄 butter
cr猫me fra卯che, ice cream or coconut-flavoured dairy-free ice cream
100ml/3陆fl oz rum