People say they're a fade, but it's my favourite way to have a burger.
The sauce makes it; diced onion in a pan with 2 tsp sugar, some butter and oil for about 20 minutes until really jammy and caramelised. Mix the onions with diced gherkin, roughly equal parts Ketchup & mayo (i go a little heavier on the mayo) a dash of Worcestershire sauce, chives and salt.
by WalkerXXVI