Wash and clean the spring onions and cut into fine rings, also using parts of the greens. Peel, wash and slice the potatoes.
Heat 2 tablespoons of oil in a pan and fry the potatoes covered for about 10 minutes.
Whisk the egg with 1 tablespoon of cold water and season with a pinch of sugar, salt and pepper.
Carefully wash the fish fillet, pat dry with kitchen paper and cut into bite-sized pieces. First roll in the flour and then turn in the beaten egg. Fry the fish in 2 tablespoons of hot rapeseed oil for about 5 minutes on both sides until golden brown. Take out of the pan and keep warm.
Fry the strips of bacon in the hot frying fat until crispy. Now add the spring onions and fry briefly. Dust over 1 tablespoon flour and sauté briefly. Deglaze with the stock and cream. Bring to the boil and simmer for about 5 minutes.
Now fry the potatoes without a lid for another 10-15 minutes until crispy. Season heartily with salt and pepper.
Stir 3 tablespoons of medium-hot mustard into the sauce and season to taste with salt and black pepper from the mill. Briefly reheat the pieces of fish in the sauce, carefully fold in the fried potatoes and arrange on plates.
Sprinkle with chopped parsley and serve immediately.
A cool blonde goes well with it for large fur seals and apple juice for small fur seals.
If you like, you can also serve a simple, green salad or a simple cucumber salad.