Preparation time: 10 minutes
Cooking time: 2 hours 40 minutes

Vin de noix or "walnut wine" is a traditional French apéritif that was once very popular. It's not, strictly speaking, a wine made from walnuts, but rather a fortified red wine flavored by macerating green walnuts.

For a less caloric dish, replace the cream in the mashed potatoes with milk.

1. In an ovenproof cocotte or Dutch oven, heat the butter and brown the cut up oxtail over high heat for 5 minutes.
2. Peel and thinly slice the carrot, onions and garlic and add them to the pot. Sweat over low heat, stirring occasionally. Add the tomato paste, sprinkle with flour and cook for 2-3 minutes over low heat; season with salt and pepper and add the bouquet garni.
3. Deglaze with the red wine and walnut wine and add enough water to cover the meat. Bring to a boil.
4. Preheat the oven to 150° C (300° F). Cover the cocotte and place in the oven for at least 2 hours.
5. Meanwhile, peel the potatoes and cook them in boiling salted water. Drain and return to the pot over low heat for 2 minutes to dry them. Put through a potato ricer.
6. After 2 hours, remove the oxtail, remove the meat from the bones and keep hot.
7. Heat the cream and gradually mix some into the potatoes, stirring well until a fairly stiff consistency is reached. Keep 125 ml (1/2 cup) of the cream aside.
8. In a buttered baking dish, place a layer of potatoes, a layer of the oxtail meat and finish with a layer of potatoes. Drizzle the remaining cream over top. Sprinkle with the grated Gruyere. Place in a 180° C (350° F) oven for 30 minutes to brown.
9. Serve with a green salad.