the Croque-monsieur is a popular Parisienne fast-food snack, or sometime breakfast popular at sidewalk cafes and midnight bars.
Croque-monsieur loosely translates to "crusty mister" and is basically a french grilled ham & cheese sandwich with a notable exception: the cheese, usually gruyere, is melted on the outside of the bread.
where a single slice of bread is used,
the sandwhich is, of course, open faced.
sit a fried or poached egg on top of the cheese and the sandwich changes gender, it is now a croque-madame, or "crusty madam". why an egg makes it female? don't ask.
in Paris i established a routine. most mornings, breakfast at the Conte Cafe in the Latin Quarter on Rue Gregoire consisting of Croque-monsieur, lettuce & tomato english-style with a splash of lime juice, french fries light, no mayo --- and forgive me Mayor Bloomberg a large Coke with lemon. . . .
later several cups of cafe au lait and a book, most recently Game of Thrones, with the occasional glance at the gorgeous, long-legged passer-by's . . . . ooo la-la, être jeune à nouveau!
at the end, before the walk-away, a final buzz-boost: an demi-tasse espresso "puya" (no milk, no sugar) and a cold glass of water.
voila! je sois ready.