“I always think of the traditional dish with the egg cut in half, from top to bottom, with the yolk on the plate and the mayo coating the white of the egg,” says author Dorie Greenspan. “But when I was at Le Paul Bert, it was upside down. I asked somebody why, and they said, ‘Because the yolk sticks to the plate!’” 

Her evocation of the restaurant famed for its adherence to tradition is no accident: Indeed, though almost criminally simple, egg-mayo is a stalwart bistro staple, a dish Paris-based food writer and stylist Rebekah Peppler says she’s “seen eaten more out than in.” “Oeuf-mayo is a bistro dish,” agrees French culinary journalist Emmanuel Rubin, “not a home dish.” To wit, the iteration from Paris’ Bouillon Pigalle is France’s most-ordered dish on Deliveroo (a British online food delivery company)—and the fifth most-ordered dish in the world.