It's literally just 1:1 mustard powder and cold water, mixed together and left to sit for fifteen minutes. It packs the same sort of punch that real wasabi does, which means that while it's awesome it's also more felt than tasted, leaving me wondering what to do with it. It doesn't fit into the same sort of applications as yellow or dijon.
I want to make some ham sandwiches though, that seems like an important step.