Step 1: Make the Beef Bolognese Sauce

1. Sauté the Aromatics: Heat olive oil in a large pot or Dutch oven over medium heat. Add the onion, carrots, and celery, and sauté for 5-7 minutes until softened. Add the garlic and cook for another 1-2 minutes until fragrant.
2. Brown the Meat: Add the ground beef and pork to the pot. Cook, breaking it up with a wooden spoon, until browned and no longer pink, about 8-10 minutes.
3. Incorporate Tomato Paste and Wine: Stir in the tomato paste and cook for 2-3 minutes to deepen its flavor. Pour in the red wine (or beef broth) and simmer for 5 minutes, scraping up any browned bits from the bottom of the pot.
4. Add Tomatoes and Spices: Stir in the crushed tomatoes, beef broth, oregano, basil, and bay leaves. Season with salt and pepper to taste.
5. Simmer the Sauce: Reduce the heat to low and cover the pot partially. Let the sauce simmer for 1.5-2 hours, stirring occasionally, until thickened and rich in flavor.
6. Finish with Milk or Cream: Stir in the milk or heavy cream during the last 15 minutes of cooking. Remove the bay leaves before serving.

Step 2: Prepare the Spaghetti

1. Cook the Spaghetti: Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water before draining.
2. Make the Garlic Butter Sauce: In a large skillet, melt the butter over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant. Reduce the heat to low and stir in the heavy cream and Parmesan cheese. Cook for 2-3 minutes until the sauce is smooth and slightly thickened.
3. Combine with Pasta: Add the cooked spaghetti to the skillet with the garlic butter sauce. Toss to coat the pasta evenly, adding a splash of reserved pasta water if needed to loosen the sauce.

Step 3: Assemble the Dish

1. Plate the Pasta: Divide the creamy garlic butter spaghetti among serving plates or bowls.
2. Top with Bolognese Sauce: Ladle the rich beef Bolognese sauce generously over the spaghetti.
3. Garnish and Serve: Sprinkle with fresh parsley or basil and extra Parmesan cheese. Serve with crusty bread and enjoy!