Korean Beef Japchae

In a small bowl, combine the flank steak with 1 minced garlic clove, 1 tsp sugar, 1/4 tsp black pepper, 1 tbsp soy sauce, and 1 tsp sesame oil. Toss well and set aside while you prepare the remaining ingredients.

Bring a large pot of water to a boil and cook the dangmyeon according to package directions, about 7 minutes, until tender and chewy. Drain, then cut the noodles into shorter lengths with kitchen scissors. Toss with 1 tbsp sesame oil, 1 tbsp soy sauce, and 2 tsp sugar to keep them from sticking.

Heat 1 tbsp vegetable oil in a large skillet over medium-high heat. Stir-fry the onion and carrots for 2 to 3 minutes until just tender but still slightly crisp, then transfer to a large mixing bowl. Add 1 more tbsp vegetable oil and cook the shiitake mushrooms until lightly browned. Transfer them to the bowl. Add the remaining 1 tbsp vegetable oil and cook the red bell pepper for 1 to 2 minutes, then add the spinach, scallions, and remaining garlic. Cook just until the spinach wilts, then add everything to the bowl.

Increase the heat to high and add the marinated beef to the skillet. Stir-fry for 2 to 3 minutes, until the beef is cooked through and no longer pink.