Red Head Salad
Ein New Kochbuch. Marx Rumpolt. 1581, Transcribed by Dr. Thomas Gloning; Translated by Gwen Catrin von Berlin.

33. Nimß ein rot Häuptkraut/ schneidts fein klein/ vnd quells ein wenig in warmen Wasser/ kuels darnach geschwindt auß/ machs mit Essig vnd Oel ab/ vnd wenn es ein weil im Essig ligt/ so wirt es schöen rot.

33. Take a red head lettuce (red cabbage)/ cut it nicely small/ and poach it a little in warm water/ then cool it quickly/ season it with vinegar and oil/and when it soaks a while in the vinegar/ it gets nicely red.
Red Cabbage
Apple Cider Vinegar
Olive Oil

Clean and shred cabbage. Poach lightly in boiling water. Put into refrigerator and stir occasionally until cool. Dress with Vinegar and Oil.