Boil glass noodles for 5 minutes, rinse under cold water, and drain.
Marinate beef with 2 tbsp Bulgogi sauce for 10 minutes.
Stir-fry beef with sesame oil and garlic, then add carrot, mushrooms, and onion.
Add noodles and spinach, mix in 1 tbsp Bulgogi sauce, and stir well.
Sprinkle with sesame seeds, mix well, and serve.
