What'll it be?
What (food or drink) would you like to order? A: "Hi folks, sorry for the wait. What'll it be?" B: "I'll have the steak, please, and he'll have the burger." A: "Hey Tony, good to see you. What'll it be?" B: "Just the usual for me, Tom." A: "Whiskey and ginger ale, coming right up."
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
interrog. What (or which) do you want? (see also What’ll it be?.) “What’s yours?” said the bartender.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.