Back before my wife got sick, I used to get ambitious in the kitchen on Saturday morning. I did not really know what I was doing, but I was determined to figure out how to make moo goo gai pan. I looked in over a dozen Chinese cooking books for a recipe and it turned out to be impossible to find (this was before Google, if you can remember that). I fooled around numerous times and always came up with something edible, but never anything that would fool someone that had eaten it from a restaurant. That quest continued into my second life as a migraine-friendly cook, and I've finally come up with something that might pass for restaurant food.
Canola or other unflavored oil
Chicken cut into bite-sized pieces
Bok Choy (one bunch of baby Bok Choy works with 2 lbs of chicken)
Optional Chinese ingredients: water chesnuts, baby corn, bamboo shoots (at least one is recommended)
Soy Sauce (optional)
Kosher Salt (What could be more Chinese than Kosher salt?)
Technique and prep are important, but not difficult. Food prep is key for two reasons. First, eye appeal will help you to make the best impression. Second, food safety depends on you following the golden rule of food prep: don't put veggies where raw meat has been. So, we cut the veggies before the meat. Start with the bok choy. Cut the leafy top off and put in its own bowl. Cut off the bottom that holds it together and you have stems similar in size and shape to celery stalks. Cut the bok choy, scallions, carrots and celery into uniform thin diagonal medallions. This gives you big pieces that will cook uniformly and look nice on the plate. Set those aside in their own bowl. Water chesnuts can be purchased in pre-cut form, in various shapes. I prefer the medallions because they will cook more uniformly with the fresh veggies. Rinse the canned Chinese ingredients and put with the fresh veggies.
Peel some ginger (this is the "secret ingredient"). Grate about a tablespoon (teaspoon if you're not a ginger maniac) of ginger into its own small bowl. Custard bowls are perfect for this.
I'm lazy and I buy a lot of boneless chicken breast on sale because it's quick and easy to deal with. However, it's not necessarily the best choice for this dish. Lately, I've gone to cracked chicken breasts or my new favorite, thighs (with the bones). I buy a little extra to compensate for the skin and bone that will not be eaten, but it is a big cost saver, plus it gives you skin to work with (and bones for making your own stock). I like to fry the skin in some oil while I am boning and cutting the chicken. It's not the healthiest choice, and not strictly required, but it will add some awesome richness to the end product. It's best to rinse the chicken before cutting. Dry it with a paper towel or it will spatter when put in the oil. Wash your hands before touching anything else.
Have a large bowl standing by, as well as a cover. Either a spare glass microwave turntable or a sheet of foil will do the trick. Remove the skin from the pan and add chicken (You HAVE purchased some cheap non-metal tongs, right?). Add a bit of salt. I sometimes throw in some chicken-flavored Better than Bullion as well. When it is about halfway cooked, add half of the ginger and one or two cloves of minced/pressed garlic (and a bit of soy sauce, if you can). Leaving the liquid in the pan, remove the chicken to the large bowl and cover to keep it hot.
Saute veggies, adding a bit more salt and soy sauce. When about half way done, add the remainder of the ginger and another clove of garlic if desired. Add in bok choy tops and wilt them down. When cooked, add stock. I usually add 8 oz per pound of chicken. Heat, taste and add salt/soy sauce as desired.
To finish the sauce, it needs to be thickened. Usually, we have made a roux and added liquid to make sauces. Here, we started with the liquid and need to add a thickener. Uncooked flour is not the best choice in most cases because of the raw dough taste that it can add. The alternative is corn starch, which goes in at the end and adds no taste. READ THE INSTRUCTIONS! I've had good luck adding about two tablespoons to a cup of water to make a slurry. I stir it up and quickly add 1/2 to 3/4 of the slurry to the pan. I heat it up to a boil and QUICKLY reduce the heat. (Otherwise, the starch breaks down and will not work.) Then I simmer until the sauce is thickened to desired consistency. This is actually the hardest part, as corn starch can be unpredictable. Because it is for texture, not taste, I usually add more, rather than less, using a very thick slurry. Take a final taste (you diluted the sauce with slurry) and salt or add soy sauce as needed. Pour contents into bowl and you are ready to serve over rice.