Soak the sweet potato noodles (dangmyeon) in hot water for about 30 minutes. Drain, rinse under cold water, and set aside.

In a skillet, heat a tablespoon of oil over medium-high heat. Add the beef and cook for 4–5 minutes until browned. Set aside.

In the same skillet, add garlic and sauté for 30 seconds. Add carrots and bell peppers, cooking for 3–4 minutes. Stir in spinach and cook until wilted.

Return beef to the skillet with the soaked noodles. Add soy sauce and sesame oil. Toss together for 3–4 minutes until well coated.

Sprinkle green onions over the dish and toss gently. Cook for an additional 1–2 minutes and serve hot.