In a large pot, heat oil and add onion and garlic and sauté until translucent. Add chicken broth, water, chicken breasts, brown rice (if uncooked), salt, and pepper and bring to a boil. Reduce heat to low and simmer 20-25 minutes. Remove chicken breasts and shred off the meat with a fork.
Heat oil in a large nonstick pan. Add chicken, and sauté for about 3 minutes or until lightly browned.
Add zucchini, eggplant, onion, green pepper, and mushrooms. Cook for about 15 minutes, stirring occasionally.