Michel Gahier is a Jura name, and the bottle we get hold of is Montibulles, a sparkling Chardonnay.
It is an exceptional sparkler. The notes run wide: raisin, aniseed, salt, butterscotch, vanilla, and the faintest whisper of seaweed underneath it all. If you want to work out why people go on about Jura fizz, this is a good place to start.