Cook the Sauce

1. Heat the Oil: In a large saucepan, heat the olive oil over medium heat. Add the chopped onion, garlic, carrot, and celery. Sauté for about 5 minutes, or until the vegetables are softened.
2. Brown the Meat: Add the ground beef (or beef and pork mix) to the pan. Cook, breaking up the meat with a spoon, until browned and fully cooked through, about 8 minutes.
3. Deglaze with Wine: If using red wine, pour it in now, scraping up any browned bits from the bottom of the pan. Let it simmer for 2-3 minutes, allowing the alcohol to cook off.
4. Add Tomatoes and Broth: Stir in the crushed tomatoes, tomato paste, and beef broth. Bring the mixture to a simmer.
5. Season the Sauce: Add the dried oregano, basil, crushed red pepper flakes (if using), and a pinch of salt and pepper. Stir to combine.
6. Simmer the Sauce: Lower the heat and let the sauce simmer gently for about 40 minutes, stirring occasionally. This allows the flavors to meld and the sauce to thicken.

Cook the Pasta

1. Boil the Water: While the sauce is simmering, bring a large pot of salted water to a boil.
2. Cook the Pasta: Add the spaghetti to the boiling water and cook according to the package directions until al dente, usually about 8-10 minutes.
3. Drain the Pasta: Once the pasta is cooked, drain it, reserving about a cup of pasta water for later use.

Combine and Serve

1. Toss the Pasta and Sauce: Add the cooked spaghetti to the sauce and toss to coat, adding a bit of the reserved pasta water if needed to thin out the sauce.
2. Serve: Divide the pasta between plates, top with freshly grated Parmesan cheese, and garnish with fresh basil or parsley.