Peel the ginger and onions, cut into small pieces and place into a food processor. Puree, add remaining ingredients and process until smooth, liquified and sauce like.
Store in a tightly covered vessel in the fridge for up to 7 days. Shake well before using.
1/2 cup peeled fresh ginger 1 medium onion 1/3 cup fresh cilantro 3/4 cup kikoman soy sauce 1/4 cup rice wine vinegar 1/2 cup salad oil