
In a large skillet, brown the chicken in hot oil. Drain off the fat. In a 3 1/2 - 4 quart slow cooker combine the fennel, onion and garlic. Add the chicken. In a bowl stir together the water, balsamic, bouillon, dried oregano (if using) and the red pepper flakes. Pour over the chicken.
Cover and cook, on low, for 5-6 hours or on high for 2 1/2 - 3 hours. Stir in the fresh oregano (if using).
Cook the orzo according to the package directions; drain. Stir tomato, cheese, olives and the remaining fresh oregano into orzo. Using a slotted spoon, remove chicken and vegetables from slow cooker. Serve with the orzo.