First, prepare the mashed potatoes. To do this, peel the potatoes, cut them into small pieces and rinse them. Then put them into boiling salted water and cook for about 20 minutes. Now peel and chop the onions. Sauté them in a little oil. Add the peas and about 200 ml of water. Let the peas simmer for about 10 minutes, stirring occasionally. In the meantime, take care of the potatoes again.
When the potatoes are done, drain them. Now heat the milk. Mash or press the potatoes into small pieces, then mash again with the warm milk and the piece of butter. Season to taste with a little nutmeg. The mashed potatoes should be nice and fluffy, so add some more milk or butter flakes if necessary, the amount depends on the type of potato.
Drain the peas and mash about half of them with crème fraîche. Season with salt and pepper. Put the mashed peas first in a baking dish, then spread the non-mashed peas and the ham cubes on top. Season with a little pepper. Now pour the mashed potatoes over the pea-ham mixture and smooth it out. Spread the grated cheese over it, then place breadcrumbs and butter flakes. Leave the casserole in the oven at about 200 degrees for 25 minutes until a nice golden crust is formed.
