Benihana Ginger Dressing

Ever been to Benihana? They have the best ginger dressing on their salads. Here is the secret recipe:

1/2 C minced onion
1/2 C peanut oil
1/3 C rice vinegar
2 T water
2 T minced fresh ginger
2 T minced celery
2 T ketchup
4 T soy sauce
2 t sugar
2 t lemon juice
12 t minced garlic
1/2 t salt and 1/4 t fresh ground black pepper