Japanese Steakhouse Ginger Dressing

1/2 cup chopped onion

1/2 cup olive oil or peanut oil

1/3 cup rice vinegar

3 T water

3 T  minced fresh ginger

2 T  chopped celery

1/4 cup chopped carrot

1 clove garlic

2 T  ketchup

1 1/2 T  soy sauce

1 T sugar

1 T  lemon juice

1/2 tsp. salt

1/4 tsp freshly ground black pepper

Combine all ingredients in blender and blend until well pureed. Refrigerate until ready to serve.