Baby, there's no delectation like peculation. An inveterate fridge-snitch, I've encountered many a tasty leftover that doesn't belong to me. Some favorites:
LJ's coconut milk curry with the big juicy shrimp (I know, dear. I'm really sorry. You even hid it in the upstairs fridge at Canada House).
ALL's cashew butter (what it is it, 10 bucks for a wee bitty jar? Wicked, wicked me).
V. Cafe's marinated olives (five gallon pailfuls of juicy briny delight! By the end of the shift my apron pockets bulged with pits)(no, of course I didn't violate the health code).
A. Rose's garlic-onion jam (and you're so good at savoring your treats. I hang my head).
I can change; I swear from now on I'm a new person. I'll keep my kleptomaniacal lips off my housemates' possessions and make my own roast garlic and sweet onion jam.
For the exorcism of vampires, colds, and leftover biscuits:
Dice two and a half enormous sweet onions and throw them in a large stockpot with a long splash of olive oil. Confit them: simmer them gently forever, adding more fat and stirring if they brown & stick, while you roast the garlic and prepare the pectin. Alternatively, lay them out on an oiled baking sheet and roast them with the garlic.
Take three heads of garlic, maybe five if you have a cold, peel off the really loose papery stuff, and slice across the top so each clove has a little peep-hole. Place them in a skillet with a little bit of water and roast them at 400 till quite creamy inside. You may want to add more water or partially cover the dish.
I used Pomona's Universal Pectin because it doesn't require a mountain of sugar. It comes with directions. But you can probably get by without it if you just cook everything way down at the end.
When the garlic is nicely browned, squeeze the cloves into the onion pot and mash everything with the potato masher. Add 1/4 c. cider vinegar, the juice of one lemon, 3 tablespoons of salt, a lot of pepper, 1/4 c. brown sugar, some molasses for good measure, and 2 tsp. calcium water if you're working with Pomona. Bring it all to a boil.
Mix the pectin (2 tsp) with 1/2 c. honey and add to the onion mixture. Stir vigorously and return to a boil. Boil for a minute and pull of the heat. Pack into sterile jars & do the whole canning thing, or just put it in a quart jar or two and keep it in the fridge.
As a concentrated source of the sweet-savory-sour culinary triumvirate, this jam makes a great gift for the flavor-shy. Tell them to use it as a glaze, marinade, sandwich spread, and soup.