He could tell Crowley to stop turning up at five when he was invited for seven. Boning a duck or slicing genoise into even layers is tricky enough without an audience, especially one that casually mentions how easy it would be to conjure it all up. Or go to the Ritz.
But when seven o'clock comes and Aziraphale's labours bear their fruit, when the soufflé hasn't fallen, the hollandaise hasn't broken--then Crowley smiles at him with sharp white teeth and bright yellow eyes. Then Aziraphale knows he's got miracles in this kitchen, and dinner is the least of them.