I have this bottle of powdered mustard seed that I bought before I learned (tonight) that it needs moisture, preferably some kind of vinegar/acidic like "young" wine, to bring out the flavor. Wondered why it tasted so bland just sprinkled on food.

Hmmm...

OMG! My eyes are burning! Added a little balsamic vinegar to the powdered mustard, and got something that tasted just like horseradish. Wow! That is a dramatic change, from bland dry powder to three-alarm just add vinegar.

Now I understand the title: That mustard got all medieval on me. Damn.

Good recipe, Frank. I think I have a third-degree burn on my tongue, but good recipe. Thanks.