The next day, bring to the boil in vegetable stock and cook covered for 30-40 minutes (the cooking time will be shorter depending on the type of lentils) Add balsamic vinegar.
Steam the onions in oil, add to the lentils and season with salt and cayenne pepper to taste.
Remove the core from the apples and cut into 1.5 cm thick slices. Fry the apple slices and bananas in oil briefly on both sides. Halve the bananas crosswise. Arrange the bananas and apple slices on the lentils.