Boil the konjac noodles, then drain the water.
Julienne the onion, carrot, bell pepper, and shiitake mushrooms.
Heat cooking oil in a pan and stir-fry the vegetables.
When the vegetables are cooked, add the konjac noodles and stir-fry again.
Season with soy sauce, sesame oil, and pepper.
Serve on a plate and sprinkle with sesame seeds.