Mix the oats and linseeds with the orange juice and leave to soak for 45 minutes.
Chop the hazelnuts and almonds.
Mix the oat mixture with the chopped nuts and quark.
Wash the nectarines, pat dry, halve, stone and cut into slices.
Place the muesli in small bowls and add the puffed amaranth.
Garnish the muesli with the fruit slices and serve.