Preheat oven (electric cooker: 140 °C/circulating air: 120 °C/gas: see manufacturer). Line baking tray with baking paper.
Chop the almond kernels coarsely and put them in a bowl with coconut flakes, ground almonds, buckwheat, sunflower and pumpkin seeds. Add honey, egg white and 5 tablespoons of water and mix everything well.
Spread on the sheet. Roast in a hot oven for about 50 minutes, stirring several times. Let it cool down.
Pack the finished muesli in airtight jars or storage tins. This way it stays crunchy for longer and keeps for at least 4 weeks.