Heat olive oil in a heavy-bottom pan or Dutch oven over medium-high heat until the oil is shimmering but not smoking. Add the ground lamb, season to taste with salt and pepper, and then sear, stirring regularly until it’s a nice brown color.

Once the lamb is nicely colored, add the onion, celery, and fennel to the pan; again season to taste with salt and pepper. Turn down the heat to medium and cook, stirring regularly until vegetables have softened and all the liquid has evaporated. Add the garlic, coriander, and anchovies and continue to cook until fragrant, for 1 to 2 minutes.

Add the wine and stir well, making sure to scrape any browned bits off the bottom of the pan. Bring the wine to a boil and reduce by half. While the wine is reducing, use a piece of cheesecloth to make a sachet containing the rosemary, sage, and bay leaves. Once the wine has reduced, add the stock, buttermilk, and the sachet. Cover the pan and cook over low heat, stirring occasionally until the sauce has thickened and the lamb is very tender.

To serve, follow the cooking instructions on the pasta package. Bring the ragu to a simmer and toss with freshly cooked pasta, fresh greens, 2 tablespoons of butter, and a squeeze of lemon juice. Garnish with a generous grating of Invierno Reserve.