Pumpkin Bolognese

Step 1Heat 4 Tbsp. unsalted butter in a medium Dutch oven or other heavy pot over medium. Add 1 large white or yellow onion, finely chopped, 2 celery stalks, finely chopped, 5 garlic cloves, finely chopped, 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, and ¼ tsp. freshly grated nutmeg and stir to combine. Cover pot and cook, stirring occasionally, until onion and celery are very soft, 8–10 minutes. Uncover and continue to cook, stirring occasionally, until onion and celery are golden around the edges, about 5 minutes.Step 2Uncover pot and add 1 lb. ground beef, preferably 20% fat; season lightly with salt. Cook, stirring occasionally, until beef is very lightly browned but not crisp (it will still be pink in spots), 6–8 minutes. Pour in 1 cup whole milk and cook, stirring occasionally, until milk has evaporated and fat is pooling on surface of meat, 7–10 minutes.Step 3Pour in 1 cup dry white wine and cook, stirring occasionally, until wine has evaporated, 6–8 minutes. Add 1 cup canned pumpkin purée and 2 Tbsp. double-concentrated tomato paste; season generously with freshly ground pepper. Cook, stirring often and scraping bottom of pot, until combined and pumpkin darkens slightly, 8–10 minutes.Step 4Pour in 1 cup water, reduce heat to low, and cook, stirring occasionally, until mixture is saucy, 12–15 minutes. If meat seems dry, add an extra ½ cup water and continue cooking another 3–4 minutes. Taste sauce and season with salt if needed. Keep warm.Step 5Meanwhile, cook 12 oz. fresh tagliatelle or pappardelle or dry rigatoni, in a large pot of boiling salted water. If using fresh pasta, cook about 3 minutes. If using dry, cook until very al dente, about 2 minutes less than package directions.Step 6Using tongs, transfer pasta to pot with sauce. Add 1 cup pasta cooking liquid and 2 oz. Parmesan, finely grated (about 1 cup). Increase heat to medium, bring to a simmer, and cook, tossing constantly, until pasta is al dente and sauce is slightly thickened, about 2 minutes.Step 7Transfer pasta to shallow bowls and sprinkle with more Parmesan.