Drip, or dripping, is the fat from roast beef that collects in the bottom of the pan. When it's cold the next morning you spread it on bread. It's best when it has a little of that dark congealed gravy with it. Add a sprinkle of salt and you're done. Use good sourdough bread, not that fluffy full of air grocery store stuff.

It's like roast beef flavor concentrate, Mmmmmmm.