Soak dried shiitake mushrooms a few hours before cooking. Until it's soft, then slice it.
Slice and cut carrots, onion, red bell pepper, green onion and mushroom into strips.
After that, slice beef into small strips, add 2 tablespoons oyster sauce, 1 tablespoon soy sauce, 1 tablespoon Brown sugar, and 1/2 tablespoon sesame oil then marinated for a few minutes before cooking.
Beat 2 eggs and cook like scramble eggs but make sure it's flat like a sheet. Then, cut it into strips.
Wash and soak spinach to remove dirt. Then, boil a pot of water. When the water is boiling, add spinach and cook for around 2-3 minutes.
Drain water and rinse with cold water. Then, squeeze the cooked spinach to remove excess water, add 1 teaspoon of sesame oil and 1/8 teaspoon of salt mix with the spinach and set them aside.
Then, add some oil into a non-stick pan, turn fire to medium-high. After that, add onion and stir fry them for a few minutes. Sprinkle some salt and set aside.
Repeat step 7, then stir fried for red bell pepper, carrot, green onion (don't over stir fried green onion) and set them aside.
Pour some vegetable oil into a non-stick pan and turn on medium to high fire. Then, add marinated beef stir fried a little bit and add mushroom.
Cover the lid for a minute and stir-fry them until the beef is cooked. (Sauce will come out from the meat and mushroom. Don't discard them, add to the noodles later.)
Boil a pot of water. When the water is boiling, add the glass noodles and let it cook for 5-10mins. Then, until it is soft and drain water.
In a mixing bowl, put the cooked glass noodles. Next, add 4 tablespoons of sesame oil and soy sauce and mix them well. (You can add more or less soy sauce to your taste). Also, use a scissor to cut the noodles a few times, so the noodles won't be too long.
After that, add all the cooked vegetables, eggs and beef into the noodles.
Next, mix the noodles and topping with roasted sesame seeds.