Remove the stems from the shiitake mushrooms and slice them. Chop other vegetables into appropriate sizes.

Marinate the shiitake mushrooms with 1 tbsp soy sauce and 1 tbsp sesame oil.

Mix the seasoning ingredients: 2 tbsp soy sauce, 1/2 tbsp fish sauce, 2 tbsp mirin, 2 tbsp corn syrup, 1 tbsp minced garlic, and a pinch of black pepper.

Heat oil in a pan and stir-fry the shishito peppers over high heat.

Add the prepared sauce to the pan in 2-3 batches, letting it boil briefly each time.