Bring water to a boil for the potatoes. Peel and chop the potatoes. Cook until tender in salted water.

Heat a large frying pan with oil and butter. Add the steaks to the pan and fry for about 3–4 minutes on each side. Season with salt and black pepper.

Pour the cream into the pan, rinse the carton with water and add that as well. Season with mustard and soy sauce. Bring to a boil and simmer for about 5 minutes.

Rinse and tear the lettuce into a bowl. Wash and chop the cucumber and add it in. Season with salad dressing.

Drain the cooked potatoes well and mash them with a masher. Mix in butter and add salt if needed.

Serve the steaks with the creamy sauce, crushed potatoes, and salad.