Mortress: A dish of meats and other ingredients, cooked together; an ollapodrida.
"Now, ma belle, to supper. A pair of cold capons, a mortress
of brawn, or what you will, with a flask or two of the right Gascony. I have crowns in my pouch, my sweet, and I mean to spend them. Bring in wine while the food is dressing. Buvons my brave lads; you shall each empty a stoup with me."
Arthur Conan Doyle, The White Company , Chapter VI.