Peel, wash and dice the potatoes. Heat clarified butter in a large pan. Fry the potatoes for about 30 minutes, turning them occasionally until golden brown. Season with salt, pepper and oregano
Clean the mushrooms and cut off the stem ends. Depending on the size, halve them if necessary. Clean, wash and cut the spring onions into pieces
Heat the fat in a saucepan. Sweat flour in it. Stir in 1/8 l water, cream and stock. Bring to the boil and simmer for about 5 minutes. Stir in mustard. Season sauce with salt and pepper
Remove potatoes from the pan and keep warm. Add the mushrooms to the frying fat and fry for approx. 5 minutes. Fry the spring onions briefly. Add potatoes again and mix everything. Season to taste and garnish with oregano. Serve with sauce
Drink: cold beer