Just check the restaurant's menu beforehand. This is easily handled since most restaurants have a web presence and you can view their menus before leaving the house.
Many Chinese restaurants are mindful of dietary preferences and have incorporated healthy choices into their menus. One of the restaurants in my area features a "Revolution Menu" and all of the items are steamed! Make sure that there is no sauce and no MSG!
Two Chinese restaurants in our area have steamed dishes: chicken and broccoli and chicken with vegetables. If you get the vegetable selection, be sure to as them to give you some tofu instead of the baby corn and carrots.
I would also get an extra dish for carryout to have at home. One of my favorite dinners is IP Chicken Soup with the chicken and vegetable or chicken and broccoli in the bowl.