This is a wonderfully tasty mediæval sauce which goes well with beef, venison and other meats (I think it'd be tasty with roast chicken). The original is from A Noble Boke of Cookry; the redaction, Pleyn Delit.
To make sauce aliper for rostid bef tak broun bred and stepe it in venygar and toiste it and streyne it and stampe garlik, and put therto pouder of pepper and salt, and boile it a litill and serve it.
Just before serving the meat, remove crusts from the bread and toast it, then crumble; add vinegar and let sit for five minutes. Meanwhile, crush the garlic and mince finely. Blend the vinegar and toast, adding broth and wine (you may wish to experiment with the proportions) until it's about gravy-thick, then add garlic and seasonings. Bring to a boil (it'll thicken a bit) and serve it forth.