Preheat the oven to 165 °C (325 °F).
Remove the duck roast from the package (leave it tied) and put it in an ovenproof dish. Cook the roast for approximately 2 hours, basting it in its own juices from time to time. Do not cover while cooking. It is ready once a thermometer inserted in the roast indicates that the temperature is between 65° C and 68 ° C (149 °F and 154 °F).
Remove the roast from the oven and let it rest for 15-20 minutes loosely covered with a sheet of aluminum foil.
Remove the twine and gently slice the roast. Place the slices on a serving platter and sprinkle on the Italian seasoning. Pour on the mushrooms sautéed in pinot noir and serve with new potatoes.
Put the mushrooms in a small pot with the wine and the duck stock. Add salt and pepper and cover; let simmer over medium-low heat for 25 minutes. Remove from the heat and set aside.
Put the butter and oil in a medium frying pan and cook on medium-high heat until it begins to bubble. Sprinkle on the flour and cook for 1 minute while stirring. Gradually add the mushroom and wine mixture while whisking until it reaches the consistency of a sauce which sticks to the back of a spoon. Remove the pan from the heat and serve as a side sauce for poultry and fish.
