Prepare the lamb: Slice the lamb into thin strips against the grain to keep it tender. Season with salt and pepper, and marinate in ¼ cup white wine for about 10–15 minutes while you prep the other ingredients.

Cook the pasta: Bring a large pasta pot of salted water to a boil. Cook the pappardelle according to package instructions until al dente. Reserve ½ cup of the pasta water, then drain the pasta and set aside.

Sear the lamb: Heat 2 tablespoons olive oil in a large sauté pan over medium-high heat. Sear the lamb strips quickly in batches — just until browned. Do not overcrowd the pan. Remove the lamb and set aside.

Make the sauce: In the same pan, add a little more oil and the butter. Sauté the chopped onions and garlic until fragrant and translucent, about 2–3 minutes.

Deglaze: Deglaze the pan with the remaining white wine, scraping up any browned bits from the bottom. Add the thyme leaves and broth. Simmer for 2–3 minutes to reduce slightly.

Add the cheese: Stir in the Parmesan cheese and white cheese. Add the chicken stock powder (if using) for extra flavor. Season with salt and pepper to taste. Grate the nutmeg. Simmer gently until the sauce is creamy and coats the back of a spoon.

Bring it all together: Return the seared lamb to the pan. Add the cooked pappardelle and a few tablespoons of reserved pasta water. Toss everything together gently to coat the pasta in the sauce. Let it heat through for a minute or two.

Serve: Garnish with fresh parsley and extra parmesan cheese. Serve immediately while it's hot and creamy.