Our brother in law is a professional chef. When he was starting out he worked in some swanky San Francisco restaurant for some very renowned chef. Not being coy here, really don't remember who it was. They were having a kitchen meeting, discussing what sort of specials to do for that day and Jamie, our brother in law, looked in the huge storage fridge and made a few suggestions involving food left over from the previous days, maybe a composed salad from the left over roasted vegetables and a soup from the leftover chicken tagine. This renowned chef gave him a stern look and said "no one wants to eat garbage!"
Apparently not all chefs feel this way, bc I am listening to Bill Buford's book, Heat, and much of it is about his time working at Babbo for Mario Batalia. MB apparently goes through the real garbage, in the actual trash bins, and pulls out sheep kidneys and celery tops that then make up that evenings special.
I ate garbage the other night; the last few shreds off a chicken carcass, the final 2 spoonfuls of white beans with the remaining 3 forkfuls of broccoli rabe, the scrapings from the pot of mashed sweet potatoes. It was good, but I wouldn't serve it to anyone, and not just bc there was barely enough for me.
Tonight I had leftover braised cabbage which I have been working on for 4 days, left over roasted carrots that I overcooked initially bc the bf and I got in the hottub with specialty cocktails and time sort of melts when you do that. The carrots cooked down to almost chewy nubs, very flavorful, but they stick to your teeth like a stale gummy bear. I mashed up some more sweet potato and then browned some ground beef and dumped some Raos marinara on it. This was all served together in a bowl with grated parm. And it was fabulous.
I think what differentiates leftovers from garbage is maybe a creative reinterpretation of the original dish and also quantity. When there are only 3 spoonfuls left, I don't care how creative you get, it's still garbage.
Which, apprently, some of us like.