Bob Evan's Colonial Dressing

1 Cup Water
1/8 Cup Cornstarch
1/2 Cup Vinegar, light or dark
1 Cup Sugar
1 Teaspoon Onion powder
1 Tablespoon Salt
1/4 Cup Butter or margarine
1/2 Teaspoon Pepper
1 Teaspoon Celery salt
1 Tablespoon Celery seed

Put water and cornstarch into blender on high speed for 1 minute or until smooth.
Transfer to a 2 1/2 qt. saucepan.
Cook mixture over Medium High heat, stirring constantly as you begin to add each of the remaining ingredients, stirring well after each addition.
Cook and continue stirring until it begins to thicken and become quite smooth.
Let it cool completely before pouring into a refrigerator container.
Cap tightly.