Wash and julienne the carrot and onion. Slice the green onion and green chili thinly. Keep the shapes consistent for even cooking.

Clean the mushrooms by brushing off dirt. Slice large mushrooms like king oyster and shiitake thinly, and tear smaller mushrooms like enoki and beech into smaller pieces.

Heat vegetable oil in a pan over low heat. Add minced garlic and sauté until fragrant. Stir in chili oil, chili powder, soy sauce, and sugar, cooking gently to prevent burning.

Add the prepared mushrooms and vegetables to the pan. Increase to medium heat and stir-fry until they soften.

Mix oyster sauce with a little water and pour it into the pan. Stir well to coat the vegetables and mushrooms evenly.

Season with salt and black pepper to taste. Cook until the mushrooms release their moisture and the sauce is absorbed.