Dust chicken with flour; season with salt and pepper.
In a large skillet, over medium-high heat, add olive oil and butter; add chicken and brown on all sides; remove chicken to platter.
In the same skillet, cook and stir the onion, celery, pepper and mushrooms for 5 minutes.
Stir in the tomatoes, tomato sauce, tomato paste, wine, herbs, garlic and sugar.
Bring to a boil; reduce heat; cover and simmer for 30 minutes.
Return chicken to skillet; cover and simmer for 45 - 60 minutes or until chicken is tender.
Serve over pasta and sprinkle with Parmesan cheese.