This is a really good side dish to accompany any sort of Asian-inspired night. Also fantastic if you toss some thinly sliced meats into the veggie mix, just make sure that if you’re cooking with meat, (a) cut it into small, bite-sized pieces, and (b)put the meat in the wok first.
As with all stir-fries, cook it HOT and FAST to preserve texture and flavor. This recipe involves no measurements because I want people to experiment. Also, the Hoisin varies in thickness depending on which brand you buy, so let that tailor your experience.

The goods – And remember, this is a stir-fry, so everything should be sliced thinly and/or in bite-sized pieces:
Zucchini
Summer Squash
Bell Peppers, if desired
Spanish or Vidalia Onion (something that cooks up nice and sweet)
Hoisin Sauce
Orange Juice
Vegetable Oil or Olive Oil
optional: cornstarch

The method:
Grab a wok or a big skillet (I prefer nonstick for this application) and get it screaming hot.
Add some oil and heat that up.
Throw in your veggies and toss them around. Since you’re cooking super-hot, keep things moving so they don’t burn or stick.
After 30 seconds to a minute, throw in about equal parts hoisin and orange juice. I go with about 1/4 to 1/2 cup of each. Mix everything together, reduce the heat a little, and let it bubble away for a few minutes.

If you prefer your sauce to be super-thick, then mix up some cornstarch with a little water (just enough to get a paste-like consistency) and dump that into the pan, and stir it up. It will thicken like crazy as soon as the cornstarch reaches a boil. Be sparing with your cornstarch slurry though … I used way too much and had to add water to my pot because I had effectively solidified my sauce.

This is great served over rice or long noodles. Or, since this is hoisin-based, wrap it up in a tortilla for homemade Mu Shu!