Mustard Sauce with Honey
Libellus de arte coquinaria: An Early Northern Cookery Book. 13th Century Rudolf Grewe, and Constance B. Hieatt.

VIII. Item de aliis salsas. Man skal takæ synup oc latæ til fiarthæ deld hunugh oc malæ hænnæ mæth goth ædik. Thænnæ ær fyrætiughæ daghæ goth.

8. Another Sauce One should take mustard [seeds], and add a fourth part of honey, and grind it with good vinegar. It is good for forty days.

1/2 C
Yellow Mustard Seeds
1/8 C
Wildflower Honey
3/4 C
Apple Cider Vinegar

Measure mustard seeds into a coffee grinder and process until as fine as desired. Transfer mustard to a food processor and add honey. Process mixture until combined and then add ½ C of vinegar. Transfer to a sealed container and allow to sit overnight. On the next day add the remaining ¼ C of vinegar or until desired consistency is achieved.