Remove the neck and giblets from inside the duck (if included). Cut the tail off the duck and trim excess fat from the duck. Reserve these parts for another use.
Pat the duck dry, then dust the outside of the duck with Copeland’s House Seasoning (or your preferred seasoning blend), rubbing the spices lightly into the skin. Put the duck in a roasting pan and roast, uncovered, until an instant-read thermometer reaches 150°F in the thickest part of the breasts and thighs (do not touch bone) and the juices run clear, about 2 hours.
Remove the pan from the oven and let the duck cool until it can be handled. Remove the skin and meat from the duck, reserving the bones for another use. Coarsely shred the meat.
Make the Burgundy Mushroom Sauce: Melt the butter in a medium saucepan over very low heat. Sift in ¼ cup of the flour, stirring constantly with a wooden spoon. Cook the roux, continually stirring, until it is the color of peanut butter, about 20 minutes. Increase the heat to medium-high, then add 1 cup of the mushrooms, the onion, and Copeland’s House Seasoning (or your preferred seasoning blend), and cook, stirring frequently, until the onion is translucent and the mushrooms are softened, about 8 minutes.
Slowly whisk in the beef stock, chicken stock, and Kitchen Bouquet. Bring the liquid to a boil, stirring, then reduce the heat and simmer the sauce, stirring occasionally, until it has thickened, about 20 minutes.
In a small mixing bowl, whisk together the remaining ¼ cup of flour and the wine to form a slurry. Stir the slurry into the pan, add the remaining mushrooms, and return the sauce to a simmer, stirring. Continue to simmer the sauce until it is smooth and thickened enough to thickly coat the back of a spoon, about 20 minutes.
Make the Duckanoff: Melt the Sauté Butter* in a very large skillet or Dutch oven over medium-high heat. Add the mushrooms and cook until tender, about 10 minutes. Stir in the heavy cream and 2 cups of the Burgundy Mushroom Sauce and remove the pan from the heat.
Meanwhile, bring a large pot of water to a boil over high heat to cook the pasta. Generously salt the boiling water, stir in the pasta and cook according to package instructions until it is al dente (tender but firm to the bite). Drain the pasta in a colander.
Meanwhile, bring the Duckanoff sauce to a boil, then add the hot pasta and cook, tossing, until it is just heated through and well combined.
Divide the pasta and sauce among four serving bowls.
In another large skillet, heat the oil over high heat until it begins to smoke. Add the duck and flash-fry, stirring occasionally, until heated through and crispy, about 3 minutes. Dust the duck with Copeland’s House Seasoning (or preferred seasoning blend) to taste.
Divide the seasoned duck evenly among the bowls of pasta. Garnish with minced parsley.
*Make the Sauté Butter: Let 1½ lbs. of the butter soften at room temperature. Melt the remaining ¼ cup of the butter in a medium skillet over medium heat. Add the green onions and house seasoning and sauté until the onions are wilted, about 2 minutes.
Transfer the mixture to a large bowl and refrigerate until completely cooled but not chilled.
Add the remaining 6 sticks of softened butter to the bowl and mix with a rubber spatula until it is thoroughly blended and no pale streaks remain in the mixture.
Scrape the butter into an airtight container or form it into logs and wrap in plastic wrap. The butter keeps, refrigerated, for 1 week or frozen for 3 months.