Roast the almonds in a pan without fat. Remove and chop roughly.
Wash the lemon balm and shake dry. Pluck the leaves from the stalks and chop them. Mix with sugar, rum, Sambal Oelek and oil. Mix in almonds.
Peel the pineapple and cut into 6 slices. Halve the slices and cut out the stalk.
Heat butter in a pan (e.g. in a grill pan). Fry the pineapple for 2-3 minutes on each side. Arrange 3 pieces of pineapple with almond pesto on plates.