I think a recipe book may be too direct or upfront. In theory, I would believe that a player's choice should somehow impact whether they would have info that helps them later in the game. To that end, maybe an NPC could drop a random hint on how something like a martini is made of, and it would be up to the player to decide whether that was information they would need or not. Or maybe Frank only has one recipe book and the pages are strewn about in random obscure places in the bar, which the player will have to look for.