4 large sweet onions sliced thin
Two cups water one cup sugar,
1 Tablespoon celery seeds

1/4 cup white vinegar in a stainless steel pan and bring to boil and boil one minute take off heat and put onions in with that mixture.     
Let sit and cool.
Drain well and add 1/2 cup Hellman's mayo.    
Refrigerate. and let get cold.   
Eat on crackers or sandwiches.     They are addictive.