The winning entrant will also be given £500 by the brand, which already offers customers a selection of eating challenges.
Michelle Fisher, brand manager for Flaming Grill, said: “We’re famous for our fun and theatrical food challenges, so I’m sure that many will jump at this once in a lifetime opportunity to design their own fantasy feast.
“We expect there are some incredible ideas out there and we want to hear them all – no idea is too big or too odd to be put forward.”
Entry is open until Sunday 28 June via the chain’s Create a Challenge app, which can be accessed on the Flaming Grill Facebook page or the brand’s website.