In a small saucepan over medium heat bring all ingredients, except corn starch, to a boil then reduce the heat to low. Spoon 1 Tbl. corn starch into a small fine mesh sifter. Whisk broth while dusting in corn starch, stirring constantly until well blended. Return gravy to a boil, check for desired thickness, add additional corn starch for thicker gravy. Remove gravy from heat and reserve.

In a medium bowl, sift flour into beaten eggs while whisking briskly. Whisk in soy sauce and sesame oil, then add in bean sprouts, diced ham, scallions, and black pepper.

Heat a skillet over medium-high heat, add 1 Tbl. canola oil then 1/4th of the mushrooms and water chestnuts, saute for 2-3 minutes. Ladle in about 1/2 cup of egg mixture, gently fry for 2-3 minutes per side until golden brown. Replenish oil between batches and adjust heat as needed.

Serve with brown gravy and sliced scallions.