Here's my tactic. I only go to Chinese buffets. For one thing, many dishes at my local have sauces that are a bit thinner/oily with probably less cornstarch like the shrimp in garlic and the riblets in black bean sauce. By going to a buffet you can make a better judgement on this. If the sauce seems too thick (with cornstarch) I will take a small bowl of eggdrop soup to dip the meat or veg into, washing off much of the sauce. They also have a few meat items that are not coated with cornstach or flour at all like roasted duck and fish.
Since I don't go out to eat very often, maybe only twice a month, I don't worry if some carbs sneak in on my meat and veg choices and use some fasting to make up for it!