In a large 12-inch skillet heat 2 tablespoons olive oil over medium-high heat. Add onions, celery, carrots, and garlic, sauté until tender, about 6-8 minutes.
Add ground beef and Italian sausage, stirring frequently and breaking up any large lumps, cook until meat is no longer pink, about 10 minutes. Drain off excess fat.
Add half & half. Bring to boiling. Reduce heat, simmer, uncovered for 5 minutes or until the half & half is nearly evaporated.
Stir in chicken broth and white wine vinegar. Return to boiling. Reduce heat, simmer uncovered for 15 minutes or until liquid is nearly evaporated.
Stir in crushed tomatoes, tomato paste, Italian seasoning, pepper and salt. Bring to a boil. Reduce heat, simmer un-covered for 5 minutes or until thickened.
Meanwhile, cook the bucatini according to package directions; drain pasta, reserving 1/2 cup liquid. Toss pasta in Bolognese sauce, adding reserved liquid if needed. Serve in pasta bowls sprinkled with freshly grated parmesan cheese, garnished with fresh chopped basil or parsley.