Peel the turnips and potatoes and cut into small cubes. Peel and roughly dice the onions. Peel the carrots and cut into slices. Dice the bacon.
Heat the butter in the saucepan. Sweat the onions in it over low heat while stirring. Add the bacon and sweat for a few minutes over a little more heat. Add the potatoes, turnips and carrots. Also sweat well, then deglaze with the stock. Bring to the boil, add the sausages and let everything simmer for 30-45 minutes.
Season the stew with salt and pepper. If you have a sensitive stomach, you can add a little cumin.