Gruel's list is a paper note in Fallout 4.
Location
It can be found on Gruel after he is killed. It contains the list of his inventory as a 'shopping' list.
Transcript
Gruel's Shopping List
- Few pounds of yao guai meat
- Half dozen deathclaw eggs
- Mirelurk meat, softshell only!
- Beer. Lots.
- A cuppa Glowing one blood
(what they don't know won't hurt 'em)