The Sandwich Sancerre is a Loire goat-cheese sandwich keyed to one place, the Sancerre hillside of the Berry, and the cheese that carries it is the crottin de chavignol. Chavignol is the village across the valley from Sancerre, and its cheese is a small flat goat's-milk puck with a firm bloomed rind and a paste that runs from supple and lactic when young to dry, crumbly, and sharply mineral as it ages. The build is a sturdy crusted loaf split lengthwise, the crottin sliced into rounds or pressed into a smear, and the rest of the build kept spare so the goat tang stays in front.
The logic follows from how concentrated the puck is. The cheese is small and dense, so it carries a lot of flavour per slice but very little fat depth or salt, which is why the supporting cast is restrained by design: a thin film of butter or a thread of walnut oil bridges it to the crust without competing, a turn of pepper or a few green leaves supplies freshness, and a touch of honey is the one sweet note the lactic paste takes cleanly. The Sancerre register is the reason to read this one as its own sandwich rather than a generic chèvre: this is white-wine country, the cheese cut from the same chalk-and-flint hills, and the build leans crisp and mineral to match, sharp rather than soft. Age is the real variable, a young crottin smearing creamy and gentle, an older one slicing into firm chalky rounds with a flinty bite. The bread needs a real crust because the filling brings no structure of its own, and the cheese is best near room temperature, where the paste opens; cold it tightens and goes mute.
Variations stay on the Loire's own goat-cheese rack rather than leaving it. The cheese in its own right is treated as the Sandwich Crottin de Chavignol; the Touraine's ash-rolled log, the Sandwich Sainte-Maure-de-Touraine, is the same goat register met in a different shape and a longer finish; a drier, more aged crottin trades the smear for sharp mineral rounds. Each holds the Sancerre-country goat cheese constant and adjusts only its age or what sits beside it. It belongs with the cheese sandwiches the catalog groups under Baguette Fromage. Its specific contribution is the crottin read through its Sancerre place: a small dense goat puck framed crisp and flinty to match the hillside it comes from.