In a small saucepan, bring 2 cup broth to a boil. Stir in rice. Remove from heat; Cover and let stand for 5 mins.
Meanwhile, in small bowl, combine cornstarch and remaining broth till smooth; set aside. In skillet or wok stir fry chicken in herb butter, yellow squash, zucchini and onion for 5 mins or till chicken is no longer pink. Add Garlic; cook 1 min longer. Stir in lemon juice, oregano, salt and pepper. Stir cornstarch mixture and add to pan. Bring to a boil; Cook and stir for 2 mins. or till thickened. Serve with Rice.