The key to making chow mein is that the noodles are fried separately from the topping (the meat, vegtables and gravy). The topping is then served over the noodles.
Feel free to create your own meat and vegetable toppings to serve over the noodles - chow mein is a great way to use up leftovers. Or, try this basic recipe for Chicken, Pork or Shrimp Chow Mein. Just use the instructions here instead of the instructions for preparing dry wonton noodles found in the recipe.