Mix flour and salt. Add eggs, milk and mineral water. Mix everything with the whisk of the hand mixer. Leave to swell for about 30 minutes. In the meantime, wash the apples and cut out the cores.
Cut apples into slices and sprinkle with lemon juice. Roast the oat flakes in a pan and set aside. Heat a teaspoon of oil in the pan and add a quarter of the dough.
Bake until the edge becomes firm, then cover with apple rings and continue baking for 1 minute. Turn and bake for about 2 minutes. Keep warm. Prepare remaining pancakes in the same way. Arrange on plates with yoghurt.
Serve sprinkled with oatmeal.