The Croissant aux Amandes Garni is what happens when a French pastry that has already been used twice gets pressed into service a third time. The base is the day-old croissant aux amandes itself, the bakery's thrift trick in which yesterday's plain croissants are split, soaked in rum syrup, packed with frangipane, dusted with sliced almonds, and re-baked until the outside crackles and the inside turns dense and butter-rich. That pastry is already a recycled object. The garni version takes it one step further and stuffs it with a savoury filling, almost always chèvre, honey, and a few crushed walnuts, occasionally a slice of jambon de Bayonne for those who want the salt-and-sugar register pushed hard.
The sandwich works at all because the underlying croissant has been transformed by its second bake. A fresh croissant collapses under any filling more substantial than a slice of cheese. The almond version, on the other hand, has been saturated with syrup and re-set in the oven, which gives it a structural rigidity closer to a cake than a pastry. It can hold a wet filling for the length of a brunch service without going soft, and the frangipane already inside it does the work of a spread. The savoury elements are essentially garnishes on a base that is already a complete object. Eaten warm, with the chèvre just beginning to soften against the still-tepid almond cream, the sandwich reads as a brunch dish rather than a lunch one.
The version is mostly a boutique-bakery phenomenon, found at the kind of Parisian patisserie that also sells the Mont Blanc and the religieuse café, and not really part of the daily sandwich shelf. The closer relative is the Croissant Garni tradition, which uses the plain laminated croissant as a savoury vessel rather than a sweet one. Some bakeries also offer a foie gras and fig variant of the same almond-croissant base, which pushes the sweet-savoury balance further toward dessert. The form does not travel especially well outside Paris, which is part of why it has not standardised into a fixed recipe. Every shop's version answers a slightly different question about how much sugar a savoury sandwich can absorb before it stops being a sandwich.