Put Miracle Whip in a bowl. Add the grated onion, curry ketchup and the remaining ingredients. Gradually add the condensed milk and stir.
Depending on how thick you want the sauce to be (usually rather thick), you dilute it with the condensed milk. Add seasoning and leave to stand for about 1-2 hours.
Important:
Use only the specified ingredients. The sauce will not work with other mayonnaise or ketchup. Do not prepare the sauce until the day you eat it - it quickly turns bitter on the second day. The sauce tastes great with meat, fish, scampi or just with bread.