To the same saute pan in which the chicken was cooked, add onion, bell pepper, and mushrooms and saute until the onions become translucent. Add tomatoes, parsley, and basil, Italian seasoning, and return the chicken to the saute pan. Cover and let simmer until the chicken is fork tender, about 25 to 35 minutes.
For the rice:
Bring chicken stock to a boil. Add rice, salt, butter and Italian seasoning to the pot of boiling chicken stock, return to a boil, cover and let simmer for 20 minutes. Remove pot from heat and let stand for an additional 5 minutes covered before removing lid.