Ironically and paradoxically, Dijon mustard can be found in neighboring countries, because non-French people don't eat as much of the stuff. In France the minute any inventory shows up anywhere it's immediately depleted, whereas in other countries it can remain on shelves for weeks.

Changing the allotment between France and other countries for exporting firms takes time, and so it does happen that more mustard is sent to countries that don't much care for it, while the French are deprived of it.

But at what price? ;)

Maybe it's more lucrative for French companies to sell it for 2x to the Swiss instead of locally.