Bring to a boil about 1.5 l of water with a pinch of salt and sugar. Wash sago under running water, strain and stir into the boiling water. Simmer for about 30 minutes, stirring constantly, until the balls become translucent. Then drain and quickly rinse with cold water. Transfer to a custard dish or small bowl and refrigerate. Bring the coconut milk to a boil, grate the ginger over it and let it cool. Boil the palm sugar with 250 ml of water to a thick syrup. Peel the pineapple, remove the stalk in the middle and cut the flesh into slices about 1 cm thick. Turn the sago pudding out onto plates and garnish with pineapple slices. Drizzle with coconut milk and sugar syrup and serve.