Season chicken with salt and pepper. Heat oil in frying pan and brown chicken pieces on all sidea. Transfer chicken to large pot and keep warm. Add onions to frying pan and saute until translucent. Add curry powder and tomato sauce. Stir until smooth, then add 1 cup broth. Bring to a boil. Add parsley, thyme, and bay leaves. Pour mixture over chicken pieces. Simmer for 1 hour, or until chicken is tender. Combine peanut butter with 2 cups broth over low heat. Season with salt and pepper. When sauce is smooth, pour over chicken. Simmer for 10 to 15 minutes more. Serve with rice.