There are actually a few different ways to fry beehoon. I normally do the “dry” variety. The beehoon is soaked. The rest of the ingredients are pretty much dry. With an adequate amount of oil and no liquids added (except for some oyster sauce), the beehoon will turn out al dente. That’s the usual way I do it.
Beehoon can also be fried “wet”. Some stock or water is added (not too much) and it should dry up after a couple of minutes of frying.
The result is a softer beehoon. The taste of the egg tends to be stronger with this cooking method. So depending on your mood or personal preference, you may want to experiment with a few methods. There is no right or wrong way here. Just keep experimenting.