Boil the potatoes and cut them into slices. Dice the onion and sauté in a small pan in a little oil. Remove the onion from the pan and now lightly fry the bacon cut into sticks (please not too dark).
Add a little oil if necessary. Set aside the fried bacon with the onion.
Now prepare the béchamel: To do this, brown the flour in butter and then pour in milk (don’t forget to stir!).
Cook for about 5 minutes, then remove from heat and season with salt and nutmeg. Then mix the béchamel with 1-2 eggs and cream, depending on the consistency. The béchamel should be nice and creamy.
Then mix the potatoes into the béchamel. Grease a baking dish (4 portions) and sprinkle with breadcrumbs. Now pour half of the potato mixture into the baking dish so that the bottom is well covered.
Then cover it alternately with cheese, bacon and onions. Note: Use only 3/4 of the cheese, the rest is needed for sprinkling. Now fill up with the rest of the potato mixture.
Finally, sprinkle the casserole with breadcrumbs and remaining grated cheese and top with butter flakes. Bake at 180 °C for about 40 minutes until golden brown.
Do not place the baking dish in the middle but a little lower in the oven.