There’s an inherent structural problem with a bagel sandwich: Eaten properly, with one’s hands, of course, there is an inevitable falloff of seeds. Half of those poppy, sesame and even browned onion bits always seem to end up on the plate—or one’s lap. (The struggle is real.)
Enter the inverted-bagel grilled cheese sandwich situation at Sadelle’s in New York, where the team takes one of baker Melissa Weller’s chewy and small-ish bagels, slices it in half, flips it inside out, sandwiches layers of American and Muenster cheese in the middle, and then throws it onto a griddle for toasting and melting. The result is dripping with cheese that clings to all of those seeds.
Source: Everything Bagel Grilled Cheese
Q: How do you keep the cheese from leaking out the hole at the bottom?
Strategic cheese placement, and mayonnaise.
Mayo can act as a sort of sealant, and you can put just enough that it prevents the cheese from spreading out too far. When I make a grilled cheese on sandwich bread, I spread the thinnest ever amount of Cains/Best Foods mayo on the inside before putting down my cheese.
I also find that the barrier it creates prevents the bread from cooking through completely, so you have a nice crusty crust on the outside, with slightly softer bread inside, and goopy cheese inside of that.
Now if you’ll excuse me, I’m off to get second breakfast.