Our version is made in conjunction with a simmered dish. That is, root vegetables are boiled/steamed until tender in either a pot, an ovenproof dish, or a roasting pan together with a meat dish. 

The meat, possibly marrow bones, and the "soup vegetables" for the stock/sauce are placed at the bottom of the ovenproof dish and seared at 225 degrees Celsius (437 degrees Fahrenheit) (fan-forced) for 10 minutes in the oven. The dish is taken out and the temperature is lowered to 150 degrees Celsius (302 degrees Fahrenheit) (conventional). Add stock/water to the meat, cover the dish with foil, and put it back in the oven.

After 1.5 hours, the root vegetables should be cut into smaller pieces and placed in the stock in the dish. Cover again and cook for at least 1 hour at 150 degrees Celsius (302 degrees Fahrenheit).

Take the root vegetables and a little bit of the stock from the dish and put them in a thick-bottomed pot. They should be mashed (either with an electric beater or a potato masher) while adding cream, butter, salt, and pepper.

Add a little milk if the consistency is still too thick.

Finally, season to taste with lemon juice, vinegar, salt, and pepper.

The dish is ready to serve.