1 sm. onion, chopped
1/4 c. vinegar
1 tbsp. Worcestershire sauce
1/3 c. ketchup
1/2 tsp. salt
1 tbsp. fresh parsley, chopped
1 c. salad oil

In blender or food processor, put all ingredients except oil. Process x 30 to 45 seconds. Add oil in steady stream while machine is running. Makes 1 pint.