The word "garbage" originally referred to entrails and offal. It appears quite frequently in old recipes. Here is how it's used in a fifteenth-century cookbook:
Take fayre garbagys of chykonys, as the hed, the fete, the lyuerys, an the gysowrys; washe hem clene, an caste hem in a fayre potte, an caste ther-to freysshe brothe of Beef or ellys of moton, an let it boyle; an a-lye it wyth brede, an ley on Pepir an Safroun, Maces, Clowys, an a lytil verious an salt, an serue forth in the maner as a Sewe. --Medieval Cookery
[Take some nice garbage of chickens, such as the head, the feet, the livers, and the gizzards; wash them clean and put them in a nice pot, and add fresh beef or mutton broth, and let it boil. Add bread, pepper, saffron, mace, cloves, and a little verjuice* and salt, and serve it as a pottage]
"Fayre" would have been the opposite of "foul," as "nice" is now the opposite of "nasty." The bread was used for thickening, a pottage is a soup or stew, and verjuice is (according to the OED) "the acid juice of green or unripe grapes, crab-apples, or other sour fruit, expressed and formed into a liquor." Actually it all sounds pretty good, but I'd substitute lamb for the chicken innards.