Wash the apples, remove the stalk and flower and chop with the skin and core with a coarse grater. Put in a sealable container and mix with the oat flakes and lemon juice. Sprinkle the raisins, sunflower seeds, cashews and hazelnuts on top and stir in with the yogurt and milk. Add the flaxseed, cinnamon and cardamom and process to a smooth mass. Remove the shell from the physalis, wash and halve to taste and drape on top of the oats. Close the jar and leave to rest in the refrigerator overnight.
Makes the ideal breakfast when you want it to be tasty but have to be quick in the morning.