Combine sesame oil, ginger, soy, water, vinegar and garlic in a screw top jar. Shake well to combine.
Toast sesame seeds by placing them in a dry sauté pan on medium low heat. Heat them slowly until they begin to brown slightly. Watch closely and remove them from the heat before they burn.
Let stand for at least 15 minutes before using.
If possible, make earlier in the day to allow the flavors to develop.