Step 1: Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Add the onion, carrots, and celery. Sauté for 8-10 minutes until the vegetables are very soft and starting to sweeten.
Step 2: Add the minced garlic and cook for another 60 seconds until fragrant, being careful not to burn it.
Step 3: Increase the heat to medium-high and add the ground beef and Italian sausage. Cook, breaking up the meat with a wooden spoon, until browned and cooked through.
Step 4: Pour in the red wine to deglaze the pan. Stir well, scraping up all the browned bits from the bottom. Let the wine simmer until it has reduced by about half.
Step 5: Stir in the tomato paste and cook for 2 minutes. Then add the crushed tomatoes, beef broth, oregano, and the bay leaf.
Step 6: Bring the sauce to a very gentle boil, then immediately reduce the heat to low. Cover partially and simmer for at least 2 hours, stirring occasionally.
Step 7: Remove the bay leaf. Season with salt and pepper to taste. Serve hot over your favorite pasta and garnish with fresh herbs.