Soak dried shiitake mushrooms in warm water for several hours until soft and pliable. Once softened, squeeze out excess water and slice thinly.

Boil the sweet potato noodles for about 3 minutes until soft but still slightly chewy. Drain and transfer to a large bowl.

Cut the noodles into more manageable lengths using scissors. Toss with 1 tablespoon each of soy sauce and sesame oil to prevent sticking.

Using the same pot of hot water, blanch the spinach for just 1 minute. Rinse in cold water three times to stop cooking and preserve color.

Squeeze excess moisture from spinach, cut into 5cm pieces, and season with 1/2 tablespoon each of soy sauce and sesame oil.

Heat a pan with a few drops of olive oil and stir-fry carrot matchsticks for 30 seconds. Remove and set aside.

In the same pan, stir-fry sliced onion until translucent. Remove and set aside.

Stir-fry the sliced white mushrooms until softened. Remove and set aside.

Quickly stir-fry the green onions until slightly wilted. Remove and set aside.

Stir-fry beef strips with prepared shiitake mushrooms until well-cooked. Add minced garlic, 1/2 tablespoon soy sauce, and 1/2 tablespoon sugar for the last 30 seconds of cooking.

Combine all cooked ingredients in the large bowl with noodles. Season with remaining 2 tablespoons soy sauce, 2 tablespoons sesame oil, remaining sugar, and pepper.

Mix thoroughly until all ingredients are well coated with the sauce. Sprinkle with toasted sesame seeds before serving.