Trim the root base off the enoki mushroom cluster (about 1 inch) and discard. Separate the mushroom strands gently with your fingers and rinse briefly under cold water to remove grit. Drain well and pat dry with paper towels; set aside.

Mince aromatics

Peel and finely mince the garlic. Peel and grate or mince the ginger. Trim and slice the scallions thinly on a bias, keeping white and green parts separate.

Make sauce

In a small bowl combine soy sauce, oyster sauce, sesame oil, rice vinegar, sugar, chili flakes, and 2 tablespoons water. Stir until sugar dissolves. Taste and adjust salt if necessary.

Stir-fry

Heat a large nonstick or carbon-steel skillet or wok over medium-high heat until hot. Add 1 tablespoon vegetable oil and swirl to coat. Add the minced garlic, grated ginger and the white parts of the scallions. Stir-fry for 20–30 seconds until fragrant but not browned.

Add the enoki mushrooms to the pan and toss quickly with the aromatics. Pour the prepared sauce over the mushrooms and stir-fry for 1 to 2 minutes, until mushrooms are just wilted and heated through. If the pan seems dry, add a splash extra water (a teaspoon at a time).

Turn off the heat. Drizzle with sesame oil, add the green scallion slices and sprinkle toasted sesame seeds over the top. Toss gently to combine and transfer to a serving plate. Serve hot as a side dish or over steamed rice.