I'm going public with my famous Mt Tabor Onions. I would have broken it out before Thanksgiving but the systems were not yet in place to accommodate the seismic reaction that is bound to follow the unveiling. Now that everything is set, I can tell you.
I have been honing my onion process for a few years now. My mother used to make them with heroic effort out of her tiny kitchen on w 12th st. She hosted countless Thanksgiving feasts in our wee apartment that would have made Standish proudish. Watching the amazing food pour out of our closet kitchen was like watching 20 clowns climb out of a Mini.
They are basically baked whole onions and they are hard to screw up. They don't take up a lot of oven space, they are inexpensive, you can make them the day before, it is almost impossible to overcook them, and they weather the turmoils of leftoverism with tasty grace. Plus, it's fun to throw a whole onion on someone's plate.
Get enough small to mid sized yellow onions to sardine fit into a square or rectangular Pyrex or some such dish.
Chop the tops and the bottoms off making two planes parallel to the horizon. Peal the outer skin off. Then, with a paring knife, slice out a little trough, creating a peak in the center. Throw the conical onion off-cut into the stuffing or something.
Drip a puddle of balsamic and drop a pad of butter into the trough of each onion. Put a 1/4"-1/2" chicken broth in the pan and liberally sprinkle with salt and pepper.
Throw it in the oven at 325 or 350 for about 3 hours and serve them up. One each.