Ranging from mild to very hot, these wide varieties of mustards originated in European countries; but have developed a following on this side of the ocean.
Most of these mustards can be found in store gourmet departments, specialty food shops, or ordered on-line, and make fine companions to American and Asian mustards.
Source: Antol, Marie Nadine: The Incredible Secrets of Mustard (NY: Avery Publishing, 1999).