If the desire for a Burger King ever intrudes upon your life (total cost around £40 if there are five of us here) then try this instead. Its obviously not BK but its not bad at all.
Good quality beef burger grilled on a griddle.
Toast the sliced side of the burger buns.
So far, so normal. But now:
A squeeze each of ketchup and mayo onto the bottom bun. A couple of slices of pickled gherkin (remove later if you really dont like them but you need it to get BK style taste)
Layer on your burger. Maybe add a couple of thin slices of raw onion.
Top the burger with your toasted bun top.
Wrap the whole thing in grease proof paper and pop it into the oven for about 10 minutes.
Oh, I forgot about adding your own cheese, bacon, mushrooms etc as we have them 'straight up' but I am sure it would work especially if you use that weird sliced cheese, which is nothing like actual cheese.