Pre-heat a griddle pan over medium heat and brush it with some oil.
In a large mixing bowl, whisk the eggs, then stir in the ham, bean sprouts, carrots, mushrooms, bok choy, water chestnuts, bell pepper, scallions, grated ginger and garlic. Season with salt and pepper and mix until completely combined. Using a large spoon, drop about 1/2 cup of the mixture onto the pre-heated and oiled griddle. Cook like a pancake, about 2-3 minutes per side, until golden, and repeat with the remaining mixture.
Meanwhile, combine the cornstarch with a splash of chicken stock to dissolve. Place the remaining stock, Tamari, dissolved corn starch, hot sauce and sliced ginger in a small pot. Bring to a boil, then thicken for 3 minutes or so, so that it coats a spoon. Remove the sliced ginger and turn off the heat.
Serve two Egg Foo Young cakes per person, with gravy poured over the top.