Steak is a boss that you have to fight in Paper Mario: Color Splash. He is sent out by an unknown character, presumably Larry Koopa, and orders Mario to prepare it for him to make up for getting the Toads food first.
The battle takes place. The Steak will flop on to you, dealing twenty damage. In order to beat it, you have to put salt and pepper, lemon juice on it and grill it. This can be done with the use of thing battle cards.