In a bowl, add in the ketchup, mayonnaise, sugar, sweet relish and rice vinegar. Mix it all well and set aside.
To make the onion topping , in a saucepan ,add in some olive oil and chopped onions. Add a little bit of water and cook it slowly till caramelized.
Cut the potatoes into fries and let it sit in cold water for 1 hour. Fry till golden.
Top the fries with cheddar cheese and melt with a broiler.
Top with some caramelized onions and then the sauce. Top with some chili flakes and dried parsley for extra flavor!
Serve while still warm!
