Made a veggie version tonight: no beef or egg, a big handful of roasted mushrooms instead. Added finely minced fresh ginger in same volume as garlic, used sliced peapods and escarole as the veggies, added a few slices of Fresno chili (and would add more next time). Due to shellfish allergy I always use a vegan mushroom-based “oyster” sauce and I used a mushroom dark soy so there was a ton of umami. Think I enjoyed this even more than the original.
ETA: start stir fry when your noodles have only 2 minutes to go. I started mine when the noodles were 3 minutes out and the veggies were just slightly overcooked for my taste.