Finely chop the onion, carrots, and celery. Mince the garlic.

In a large pot or Dutch oven, heat the olive oil over medium-high heat. Add the ground lamb and cook until browned, breaking it up with a spoon as it cooks. Once browned, remove the lamb from the pot and set aside, leaving any rendered fat in the pot.

In the same pot, add the chopped onion, carrots, and celery. Cook over medium heat until the vegetables are soft, about 8-10 minutes. Add the minced garlic and cook for another 1-2 minutes until fragrant.

Pour in the red wine and stir, scraping up any browned bits from the bottom of the pot. Let the wine simmer until it has reduced by half, about 5 minutes.

Return the browned lamb to the pot. Stir in the crushed tomatoes, tomato paste, and broth. Add the dried oregano, thyme, and bay leaf. Season with salt and pepper to taste.

Bring the mixture to a boil, then reduce the heat to low and let it simmer uncovered for 1.5 to 2 hours, stirring occasionally, until the sauce has thickened and the flavors have melded together.

About 15 minutes before the ragu is ready, cook your pasta according to the package instructions until al dente. Drain the pasta, reserving a cup of the pasta cooking water.

If the ragu is too thick, you can add a bit of the reserved pasta water to reach your desired consistency. Toss the cooked pasta with the lamb ragu until well coated. Serve the ragu over the pasta, garnished with fresh basil or parsley and a generous sprinkle of grated Parmesan cheese.