Trim off the bottom of the enoki mushrooms and clean them thoroughly.
Slice the onion thinly and chop the green onion.
Heat cooking oil in a pan and stir-fry the onion and green onion.
When the onion turns translucent, add the enoki mushrooms and stir-fry.
Add soy sauce, sugar, minced garlic, and pepper, and stir-fry until the flavors are absorbed.
Place the sautéed enoki mushrooms over rice, then sprinkle seaweed flakes and roasted sesame seeds on top to finish.