Peel and thinly slice the onions and shallots.
Remove the peel from the garlic by cutting off the bottom.
Break up the cloves in a large bowl.
Place another bowl on top and shake vigorously.
The peels come right off. Like magic!
Add the olive oil to a Dutch oven or heavy bottomed pot. Add the onions, shallots, and garlic.
Cover and cook for 20 minutes, stirring occasionally.
They will start to soften and turn translucent.
Remove the lid and add red wine, balsamic vinegar, and brown sugar.
Cook for another 30 or so minutes, or until the onions are caramelized. Add fresh thyme and season with salt and pepper. If you still have large cloves of garlic remaining, use a fork to mash them up and stir into the jam.