Sauté: In a medium size saucepan or a Dutch oven, heat the oil on medium heat. Add the soffritto (carrots, celery, and onions) and cook for about 7 minutes, until the vegetables soften (you aren't browning them). Add a pinch of salt and black pepper.
Cook beef: Add in the ground beef (you could do ground beef and ground pork). Break up any large lumps and cook until the meat is no longer pink, about 10 minutes. If you would like to use diced pancetta, add that in now (totally optional). Keep stirring frequently. Add in the herbs and stir to combine. Season with salt and black pepper.
Reduce wine: Add in the wine and stir to combine. Let the wine reduce.
Add tomatoes: Stir in the tomato sauce and cook over medium low heat until the sauce thickens, which could take 2-3 hours, stirring every 20 minutes. Make sure the sauce is not boiling, it's supposed to be a low simmer. Check the flavor and season with a bit of salt and pepper, if needed. Don't forget to keep coming back to check the sauce and stir so the sauce doesn't stick to the bottom of the pan. Also, it may be thickening up and you'll have to add some water to it to loosen it up a bit. I simmer my ragu (Bolognese sauce/meat sauce) for about 2 hours. You could make this a day ahead.
Optional: After you've added in the tomatoes, you could transfer the sauce to a slow-cooker and let it simmer on high for 3 hours or low for 6 hours.
Serve: When the sauce is ready, remove the bay leaf. Heat the sauce and serve over cooked pasta. ENJOY!