Peel and core fruit and cut into 1 centimeter / 1/3 inch slices. In a frying pan, heat the butter and sugar, stirring until the sugar is melted, then stir in the ground cardamom seeds. Make a single layer of the fruit, spooning the liquid over the top, and cook until just warmed through.
Lift out of the pan into serving dishes, and do a second batch in the pan if necessary. Serve with whipped cream or ice cream (or accompaniment of your choice!).