In a medium bowl, toss chicken breast pieces with the poultry seasoning; set aside.
In a 5- to 6-quart Dutch oven, heat 1 tablespoon of the oil over medium heat. Add mushrooms, carrot, onion, sweet pepper, garlic, dried basil and parsley (if using), black pepper, and salt; cook for 10 minutes, stirring occasionally. Remove vegetables from Dutch oven; set aside.
Add the remaining 1 tablespoon oil to the Dutch oven; heat over medium heat. Add chicken pieces; cook about 5 minutes or until browned, stirring occasionally. Return vegetables to Dutch oven. Stir in the water and chicken bouillon granules. Bring to boiling; stir in potatoes and barley. Return to boiling; reduce heat. Cover and simmer about 15 minutes or until potatoes are tender. Stir in fresh basil and parsley (if using).