Prepare the seasoning sauce by mixing chopped green onion, chili, sugar, sesame seeds, soy sauce, minced garlic, sesame oil, and chili powder. Adjust soy sauce if too thick.

Wash and soak dried shiitake mushrooms in water until soft. Remove stems and chop them finely. Save the soaking water for future use as broth.

Mix ground beef, chopped green onion, chopped onion, and chopped mushroom stems with an adequate amount of seasoning sauce. Stir gently with a fork to avoid tough texture.

Stuff the softened shiitake mushrooms with the beef mixture and place them in a steamer. Steam for 10 minutes.