Preheat the oven grill to 250 degrees.
Finely chop the rosemary needles (1). Spread evenly on the inside of the boneless gigot. Roll this up tightly and tie with kitchen string. Season heartily with salt and pepper. Place the gigot in a roasting pan and brush with olive oil.
Meanwhile, brown the gigot in the heated stove on the middle rack for fifteen minutes.
Turn off the stove and open it to allow the heat to escape. Once the heat is still about 75 degrees, close the oven door repeatedly and cook the lamb gigot roast at this heat for 1 3/4 to 2 hours.
Place the garlic, onion halves, carrots and celery in a roasting pan with the rosemary sprigs (2), red wine and stock. Cook over high heat until reduced by just over half. Strain the sauce, squeezing out the aromatic ingredients.
Just before serving, bring the sauce to a boil repeatedly. Add the cream. Add the butter in flakes and work it into the sauce. Season to taste with salt and freshly ground pepper. Serve the sauce separately with the gigot.
A mixed vegetable with diced potatoes goes well as a side dish.
Our tip: Use sweet red wine for a sweet note and rather dry wine for flavorful, spicy dishes.