- Boil the potatoes whole in their skins for 15–25 minutes, depending on their size. Drain, then cut into a mixture of halves and quarters.
- Heat the rapeseed oil in a large frying pan and add the potatoes. Cook, turning regularly, for 3 minutes.
- Add the mushrooms to the pan with the potatoes and cook, stirring, for another 3 minutes, then add the spring onions and cook, stirring, for a further 2 minutes.
- Sprinkle the flour over everything and stir to mix well. Next, gradually pour in the milk, stirring constantly, for 2–3 minutes.
- Stir in the cheese, season with pepper and serve.