If using whole boneless duck legs or shredded roasted duck, shred the meat into bite-sized pieces, discarding excess fat, skin or bone. Measure about 2 cups shredded duck. Pat slightly dry with paper towel.

Sweat aromatics

Heat a large heavy-bottomed skillet or Dutch oven over medium heat. Add 2 tablespoons olive oil. When shimmering, add the diced onion, carrot and celery. Cook, stirring occasionally, until softened and translucent, about 7–9 minutes. Lower heat if vegetables begin to brown too quickly.

Add garlic and tomato paste

Add the minced garlic and cook 30–45 seconds until fragrant. Add 2 tablespoons tomato paste and cook, stirring, 2–3 minutes until the paste darkens slightly — this deepens the flavor.

Deglaze

Pour in 3 tablespoons red wine and scrape the bottom with a wooden spoon to release any browned bits. Let the wine reduce by about half, 1–2 minutes.

Combine duck and tomatoes

Stir in the shredded duck, then add the crushed tomatoes (entire 28 oz can), 1 cup stock, bay leaf, thyme sprigs and rosemary. Stir to combine.

Simmer slowly

Bring to a gentle simmer, then reduce heat to low so the ragu barely bubbles. Cover partially with lid and simmer for 30–40 minutes, stirring occasionally, until sauce has thickened and flavors have melded. If sauce becomes too thick, add up to 1/2 cup additional stock or reserved pasta water later to loosen.

Finish and season

Remove and discard bay leaf, thyme stems and rosemary sprig. Stir in 1 tablespoon butter, 1 teaspoon sugar if using, crushed red pepper flakes, salt (start with 1 1/2 tsp) and 1/2 teaspoon freshly ground black pepper. Taste and adjust seasoning. Stir in chopped parsley.

To Serve

Bring a large pot of salted water to a rolling boil. Cook pasta according to package directions until just shy of al dente (about 1–2 minutes less than recommended for dried pasta, or per fresh pasta guidance). Reserve 1 cup pasta cooking water before draining.

Return the drained pasta to the pot or a large sauté pan set over low heat. Add 1–2 ladlefuls of the duck ragu and 2–4 tablespoons of the reserved pasta water. Toss gently to coat, adding additional sauce and a splash of pasta water as needed to reach a silky consistency. Finish with a drizzle of extra-virgin olive oil if desired.

Serve the pasta topped with generous spoonfuls of duck ragu, a sprinkle of grated Parmesan and additional chopped parsley. Offer extra pepper and Parmesan at the table.