Maybe it would have to be called "Hobo Chef" or "Drifter's Grill" in order to be less degrading for potential guests, but the concept is simple: Find a stable and industrious homeless person, preferably cooperative and social. Hook him or her up with a little grill or trash barrel, and see what's for dinner. This is your "Julia Child" anchorbum. Each episode would then have a different guest from around the homeless culinary world. Then they share their favorite recipes and techniques.
This appeals to me because most of the existing cooking shows are predictable. Even the Gordon Ramsay ones where people yell and scream end up pretty much the same each time. I want to see some guy roasting a raccoon on a curtain rod, or see what sort of garnishes can be made from chickweed or dandelions. I think they could grate cheese on a perforated Mountain Dew can. I believe the true Bum Chef is out there, making something delicious out of the trash every evening, and America wants to watch him. At least, I do.
I just found a parody version of this concept already on YouTube, but it's not much good. I think this would only be worth watching if drawn from reality, with just the right fringe personalities, and the oddities of circumstance that only reality can provide.