Peel, wash and cut the potatoes into eighths. Cook in boiling salted water for 15-20 minutes. Clean, wash and slice spring onions diagonally. Clean, clean and slice the mushrooms.
Clean shiitake mushrooms, remove stalks. Cut caps into strips. Wash marjoram, dab dry and, except for something to garnish, pluck off leaves. Wash flesh, dab dry and cut into strips.
Peel onions and cut them into rings. Heat 1 tablespoon of oil in a coated pan, fry the meat all around. Season with salt and pepper and remove. Fry the mushrooms at medium heat in the frying fat, season with salt and take them out.
Add 1 teaspoon of oil to the pan. Fry the onion rings in it until golden brown, turning them over and taking them out. Drain potatoes, add milk, season with salt and nutmeg and mash finely. Add the onion rings.
Keep puree warm in a closed pot. Add the meat with the meat juice, mushrooms, spring onions, 2/3 of the marjoram and stock to the pan and bring to the boil. Add the sauce thickener and bring to the boil again. Season to taste with salt and pepper.
Arrange puree and ragout on plates. Garnish with remaining marjoram.