Photograph: Brett Stevens
Slice the top and bottom from the pineapple, then cut the flesh into vertical quarters. Peel each quarter and remove the core, then slice lengthways. Preheat the grill to high.
Melt the butter in a small pan and add the chilli, lime zest and juice, sugar and bourbon or rum. Bubble together for a few minutes.
Arrange the pineapple on baking sheets; brush with some of the syrup, then grill for 2-3 minutes. Turn the slices and brush with more syrup; grill for 2-3 minutes more. Serve with the syrup and some yogurt on the side.
Get ahead: make the syrup up to 1 hour ahead.