How I make this insanely delicious 5-onion... thing

This dish is hard to name. Read to the end of this post and you'll see what I mean.

I sort of borrowed this idea -- from Woodward's Garden, where I was working there as sous chef a loooong time ago -- but I created a riff of what is a slightly less fancy version into what is now a very highly-praised item on the menus I cook for my friends at home. Here's how to make it:

When available, I use 5 varieties of onion: yellow, white, red, green, and shallot. I cut the onions vertically into thick slices:

 ...and cook in olive oil with salt and pepper in a large, straight-sided pan:

...and stir occasionally until the onions just begin to brown:

Once the onions are golden brown, you can end up with a really good fond on the bottom of the pan; that's when to deglaze. If your nose is sensitive, try not to inhale when the vinegar hits the pan -- you'll get a sharp blast of flavor rocketing into your nostrils. If you're a more acidic person -- like me -- I like to lean in and get a whiff. It gives me a good little jolt! 

I deglaze the onions in balsamic vinegar and truth to be told, it doesn't matter what balsamic vinegar you use, as long as it's not the cheapest stuff on the grocery shelf. Choose something middle in road, and you'll end up with a richer result. Stir the onions relatively frequently and feel free to add more vinegar if you like.

The reduction I'm looking for produces these results: deeply saturated, not dry, just before the onions start to stick. If you've gone too far, and the onions are sticking to the pan, you can release by deglazing with just a bit more vinegar (or a little water) and stir the onions until they come loose. Then it's time to take them off the heat and cool to room temp.

I use these onions as a base in quite a few of my pizzas. The earthy sweetness provides a great foil for other ingredients, like those spicy greens and pretty much any cheese. You can put this creation on virtually any pizza and you can't go wrong. Everyone raves: "that's what makes the dish!"

However, this is a hard dish to name, given the whole premise is that it is comprised of five different variety of onions. I've tried calling it "relish" (sounds like burger topping), "marmalade" (too sweet and/or bitter), "chutney" (assumes a flavor profile that just doesn't make sense to me). I've also tried "five-onion balsamic braised confit," which is A) too wordy and B) too snooty. Now I've gotten this down to "five-onion balsamic confit" (less of a mouthful), but again, to be honest, "confit" means "duck or other meat cooked slowly in its own fat." Got any ideas? Send 'em to me!