Pre-cook the green beans in salted water for 20 minutes. In the meantime, peel and dice the potatoes, cut the onions into large wedges and dice the carrots.
Fry the onions and potatoes in a little fat, add the carrots and pre-cooked green beans. Dust everything with flour, deglaze with stock, milk and cream. Simmer for about 15 to 20 minutes, until the vegetables are cooked, season with salt and pepper.