while putting your favorite condiment in a sandwich, you accidentally make a magical occult symbol and summon a demon...

you silently take two more slices of bread out of the package and make another sandwich. you put it on a plate with a handful of potato chips and hand it to the demon.

he takes the sandwich, smiled and vanishes into puff of demonic smoke. the next day you get job promotion you were after.

the was no contract. no words spoken. you owe nothing. but every now and then another demon pops in for lunch.

demons don't often get homemade sandwiches