Beef, chesse, rucola (rocket salad), aioli, caramelised onions and a good bun.
pic: http://gutburgerlich.de/wp-content/uplo ... 0x1080.jpg
And no, i did not make that one. But it tastes great.
Well this is actual a burger, so not sure if it really counts as a sandwich.
Or also very good: a slice of normal hard bread, butter, hard chesse and ketchup on top.