Remove hor fun from package and tear into large pieces. Set aside.
Heat 1 tablespoon vegetable oil in a wok or large fry pan. Transfer half of the hor fun to the heated wok or fry pan and allow it to fry for 2 minutes.
Add 1 teaspoon soy sauce and flip the hor fun. Continue to stir fry for another 2 to 3 minutes until hor fun is slightly crisp. Remove and divide noodles onto 2 plates.
Repeat with the remaining half of the hor fun.
In the same wok or fry pan, heat remaining 2 tablespoons of vegetable oil. Sauté garlic for about 20 seconds.
Add sliced pork and stir fry for 2 to 3 minutes.
Add chicken broth and bring to a boil. Season with salt and ground pepper.
Add corn starch mixture, shrimp, and choy sum. Allow sauce to come to a boil and thicken for about 2 minutes. Shrimp should curl and turn pink.
Stir in lightly beaten egg and immediately turn off heat.
Add sesame oil.
Divide sauce over the 4 plates of fried hor fun.
Serve with pickled green chilies or cut red chilies in soy sauce.