"Make sure you have lots of napkins!..."
Cooking spray
ground beef
quick-cooking oats
milk
large egg, lightly beaten
small onion, minced
kosher salt
Black pepper, to taste
salted butter
small onion, minced
ketchup
distilled white vinegar
sugar
Worcestershire sauce
Dash of hot sauce
hero rolls, split
slices cheddar cheese
Pickle slices and potato chips, for serving