In a 5- to 6-quart pan over high heat, bring 2 quarts water to a boil. Add 1 pound rinsed mung bean sprouts and 1/2 teaspoon salt. Cook until sprouts begin to wilt but still retain a slight crunch, 4 to 5 minutes. Drain well and pour into a bowl.
Add 2 tablespoons white distilled vinegar, 2 tablespoons Asian sesame oil, 1 tablespoon sugar, and salt and pepper to taste. Serve at room temperature or cold.
Shortly before serving, sprinkle mung bean sprout salad with about 1 tablespoon toasted sesame seeds.