Brown chicken in oil on all sides in a large ovenproof Dutch oven. Remove chicken, and set aside; reserve oil in Dutch oven. Sauté onion, green pepper, and garlic in oil. Stir in next 7 ingredients, and bring mixture to a boil.
Add chicken, stirring gently; cover and bake at 350° for 20 minutes or until rice is tender. Add peas, mushrooms, and pimiento; stir gently. Cover and bake an additional 10 minutes or until thoroughly heated. Remove bay leaf, and serve immediately.