What’ll it be?

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.

What’ll it be?

interrog. What do you want. (see also What’s yours?.) Okay, Mac, what’ll it be?
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • What’s yours?
  • What'll it be?
  • What'll you have?
  • Make mine
  • make mine (something)
  • same again
  • (the) same again
  • blaze
  • blazes
  • blazing