Japchae (Korean Glass Noodle Stir Fry)

Name: Japchae (Korean Glass Noodle Stir Fry)
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Cuisine: Korean
Ingredients: 9 oz pork loin ((or beef, chicken) (use lean parts)); 1/2 yellow onion; 2 oz carrot; 2 oz red/yellow bell peppers; 2 oz shiitake mushrooms; 2 oz garlic chives; 4 oz Dangmyeon noodles (당면); 1/2 tbsp dark soy sauce ((optional)); 1.5 tbsp toasted sesame oil; 2 tbsp neutral-tasting oil; salt and pepper ((to taste)); 1 tbsp minced garlic; generous pinch of toasted sesame seeds ((to garnish)); 1.5 tbsp sugar; 1.5 tbsp soy sauce; 1 tbsp oyster sauce; 1/2 tsp MSG ((optional))