There are a variety of phrases that utilize steak and sizzle to compare the substance of something (or its lack of substance).
Here instead is a meat-and-potatoes guy from Girard, Ohio, who attended Youngstown State, worked for General Motors, the Department of Commerce and Merrill Lynch, and knows how to tell the steak from the sizzle.
— John Liscio, Barron’s, 19 May 1997
The boys in the kitchen think the waiters are just a bunch of fancy-pants mannequins, while the boys in the front room are sure that it's the sizzle, not the steak, that keeps the people coming in.
— Adam Gopnik, The New Yorker, 4 Sept. 2000
The sizzle, of course, is the sound the steak makes while cooking on the grill, and along with the aroma of a cooking steak might whet one’s appetite. So all sizzle and no steak has come to mean something that is enthusiastically promoted but then does not live up to its promise.
Dallas has been all sizzle and no steak when it comes to postseason success in recent years. The Cowboys are 32-16 since Prescott and Elliott burst on the scene as rookies. … The twist: while 11 teams - six in the NFC - have won playoff games since the start of the '16 season the Cowboys aren't among them.
— David Moore, The Dallas Morning News, 4 Jan. 2019