Peel and slice the pineapple, remove the hard stalk and dice the flesh. Place the pineapple in the blender jug of a food processor or a blender. Peel 2 ripe bananas, cut into slices and mix with 3 tablespoons lemon juice.
Peel 1 piece (approx. 2 cm) of ginger and dice finely. Put ginger with bananas and juice into the blender as well. Puree everything finely with 1⁄4 l apple juice. Pour into glasses and arrange with 4 tablespoons of tender fine oat flakes and 1 pinch of nutmeg.