Sort of like with the kim bap Korean rice rolls, you are preparing a bunch of vegetables separately, then combining them at the end.
Slice the mushrooms about 1/4 inch thick, then cook them in a screaming hot skillet (high heat) with 1 tbsp of vegetable oil and some salt and pepper. Cook for just 2-3 minutes until they have softened a bit.
Julienne the peppers, and cook them over medium high heat with 1 tbsp vegetable oil and salt and pepper for about 5 minutes (whenever they are softened. If you have a gas stove, this will probably take less time).
Repeat with the onions, carrots, and beef until all the components have been cooked (it can all be cooked in the same pan, but cook them separately).
The veggies and beef are all done, so it’s time to cook the noodles in some seriously salty boiling water. Glass noodles typically take a while, even though they’re thin. It should take 12-13 minutes until it’s al dente.
Whisk together the soy sauce and sugar in a skillet set over medium high heat, and add all the vegetables and beef in. Drain your noodles, and add them to the party. Garnish with some sesame seeds and pinenuts, and toss. Enjoy!