Japanese Ginger Dressing

Japanese Ginger Dressing (like at the japanese steak houses)

3 tablespoons minced carrots
2 tablespoons ginger, minced
3 tablespoons celery, minced
2 tablespoons finely chopped lemons (some rind)
1/2 cup soy sauce
3/4 cup vegetable oil
3/4 cup seasoned rice vinegar
1/2 cup water
1 medium onion, chopped (about 1/2 cup)
2 tablespoons ketchup

put all ingredients in a blender and blend until emulsified.
stir and shake before each use.