In the past on my one truck forum there was talk of how you make your grilled cheese in reference to the coating on the bread… Ive heard of many different ways one one of which is the standard to me… butter on the bread…
The one i was most curious about and use ever since learning of it is mayo! Yup regular ole mayo… no miracle whip tho…
I’ve even heard of using extra virgin oil on there…
So how do you make yours? 
i get my gf to make it… haha
Yep buttered bread to the outside.
Then lots of ketchup or raaaaaanch.
Might try the mayo…
i use bread, cheese and butter.
butter on the outside, cheese on the inside. I also add a slice of ham and a little mustard occasionally and eat a Clausen’s pickle on the side.
I make it the the reg old fashion way butter up some good bread and slap into a cast iron pan. Most diners use mayo its fast and oily and makes a good crunchy/griddled surface.