Wash, peel and halve apples and cut out the core. Cut into the apple top several times. Sprinkle with lemon juice. Boil up apple juice, 500 ml water and 25 g sugar in a wide pot.
Simmer covered over a low heat for 10-15 minutes (depending on type of apple, must not crumble). Then carefully lift it out with a skimmer and let it drip off on kitchen paper.
Meanwhile, bring milk, salt and 20 g sugar to the boil in a saucepan. Add rice and let it swell covered at low heat for about 30 minutes. Stir several times. Then remove from the stove.
Separate eggs. Mix the egg yolks and 1 tablespoon of rice pudding in a small bowl, stir into the remaining rice pudding. Beat the egg whites until stiff and fold into the rice pudding in two portions. Put the rice pudding into 4 small, lightly greased, ovenproof portion moulds or a large mould.
Place apples on top and sprinkle with muesli. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 15 minutes. Serve decorated with mint and apple wedges.