Loving this topic! l love American food and always come home a few lb heavier! Give me an hour in Trader Joe's and I'm happy.
Sandwiches with no butter does seem parsimonious to your average Brit, but obviously it's what you're used to.
I was met with a patronising incredulity from a friend from Kentucky (she sounds JUST like Scarlett O'Hara, it's wonderful) when she queried why anyone would butter, eg, peanut butter toast. 'The clue's in peanut BUTTER... you';re just putting butter on butter?' she said, horrified. No, my pal, peanut butter isn't actually 'butter' in my book!
HOWEVER she MORE than redeemed herself by giving me her recipe for 'the ultimate grilled cheese sandwich' and oh my god.... this involves melting cheese in your frying pan and setting your (mostly cooked) cheese toastie on it, waiting till it browns, then flipping, adding more cheese to the pan and repeat. (I think these are known as 'Inside-out grilled cheese'.
You end up with a crunchy, frilly layer of crispy cheese on the OUTside of the sandwich as well as oozy melty cheese INside. You have to try it to believe the deliciousness of this...
I can't find her recipe, but I see Tesco have one Ultimate Grilled Cheese Sandwich - Tesco