In a small bowl, mix together 2 tablespoons of oyster sauce, 2 teaspoons of soy sauce, ½ teaspoon of dark soy sauce, and 1 teaspoon of cornstarch. Whisk in a splash of water until smooth.

Heat 1 tablespoon of oil in a skillet over high heat for about 1 minute. Add 1 pound of cleaned, sliced mushrooms and cook for approximately 3 minutes.

Lower the heat to medium, push the mushrooms to one side, add the remaining oil and toss in minced garlic. Sauté for about 20-30 seconds.

Pour the sauce mixture into the skillet with mushrooms and garlic. Cook for 2-3 minutes until the sauce thickens.

Remove from heat and transfer mushrooms to a serving dish.