Preheat the oven to 190'C.
Peel the potatoes and then thinly slice on a mandolin.
Peel and finely dice the onions.
Heat a large frying pan and then add the olive oil. Add the onions to the pan along with 3 or 4 sprigs of thyme. Sauté for 3 minutes, stirring every once in a while. Add the balsamic vinegar to the pan and continue cooking until all the liquid has evaporated. Mix the onions with the sliced potatoes.
Line the base of a large ovenproof dish or 6 individual le creuset moulds with the potatoes and onions. Season with salt and pepper and then sprinkle over a few thyme leaves.
Bring the stock to the boil and then ladle it over the potatoes. Chop the butter into small pieces and sprinkle over the top. Transfer to the oven and bake uncovered for approximately one hour - check if the potatoes are cooked through using the tip of a sharp knife.
While the potatoes are cooking, you can prepare the rest of the dish.
Peel and slice the shallot. Chop the head of garlic in half.
Place the wine, shallot, garlic and the thyme into a saucepan. Place on the heat and reduce by 3/4. Add the veal glaze and reduce by half. Check the seasoning and add salt if required.
Cook the fillet steak, foie gras and the green beans to coincide with the pommes boulangères being ready to serve.
Cut the foie gras into slices 1 cm thick.
For the steaks: heat a frying pan until hot and add a little sunflower oil. Season the steaks with sea salt.
Colour both sides of the fillets and then flambee the steaks with the cognac. Transfer to the oven and cook for 5 to 8 minutes depending on the thickness of the steaks. Once cooked allow the steaks to rest for a few minutes.
For the green beans: bring a pan of water to the boil and add a generous amount of salt.
Cook the beans for 3 minutes in the rapidly boiling water and then drain. Season with sea salt and black pepper and serve with a knob of butter.
Heat a frying pan until very hot. Season the foie gras slices with sea salt and sear in the pan for 10 seconds. Remove the pan from the heat and turn the foie gras steak over to finish cooking.
Serve the fillet steak alongside the pommes boulangères and the green beans. Finish the dish with a drizzle of red wine sauce and the foie gras.
«When using red wine for a sauce use a full bodied wine that you are happy to drink.»