Start by removing the skin from the chicken and spread, fat-side down, on paper towels or paper plates to dry. (I'm a huge fan of paper plates in the kitchen.) Be sure to get the skins as flat and stretched as possible. Dry for 10 minutes.
Crank your waffle iron to high.
When the skins are dry, move carefully to the waffle iron; depending on your model, you may only get a couple of pieces in at a time. Do not allow them to overlap.
Cook for 5 minutes, then use a spatula or kitchen tweezers to flip and rotate the skins about 45 degrees. Continue cooking until golden brown and crisp, about another 5 minutes. Remove to a wire rack and season with salt and pepper.
Repeat until all the skins have been converted into meat crackers, stopping halfway through to carefully pour the rendered fat (schmaltz) into a heatproof bowl. DO NOT DISCARD AS THIS IS ESSENTIALLY GOLD.
To make sandwiches, brush one side of a single piece of bread liberally with schmaltz.
Place the bread, schmaltz-side down, on the waffle iron. Spread with mayonnaise then top with a layer of the skin and season with the marjoram. Spread some mayonnaise on one side of a second slice of bread and close the sandwich, mayonnaise-side down. Brush the top with schmaltz and close the waffle iron lid. Weigh the top of the waffle iron down with a cast-iron skillet or a 28-ounce can of tomatoes.
After 2 minutes, check for doneness. When you peek under the bread corner, it should be golden brown and everything should be crisp. Repeat the process with the remaining bread and ingredients.
Serve as is or cut into quarters. Serve with chicken soup or just binge right then and there with no apologies. If so, shower afterwards.