In my recent pide recipe I listed balsamic onions among my all-time favourite pizza toppings... so I thought I should share with you how I make them...
I usually do a big batch with four or so onions because I like to have a jarful on hand in the fridge to add sweetness and a rich depth of flavour to on-the-fly snacks and meals like toasted sandwiches, omelettes, pides/pizzas, and even salads. To avoid onion tears I can't recommend using a mandolin strongly enough. The super-sharp blades make light work of thinly slicing mountains of onions and - added bonus - less of their noxious vapour gets released into your eyes. Once that part of the prep is out of the way the rest of the cooking process is pure olfactory pleasure.
Balsamic Caramelised Onions Recipe
yield: fills a 500ml mason jar / time: 40 minutes
1. Slice 4 large onions thinly on a mandolin.
2. In a large pan over a medium-low heat add a good dousing of olive oil (or garlic flavoured if you have it). Pile in the onions and a pinch of sea salt.
3. Keep a watch over the pan and stir regularly to avoid burning or sticking. When the onions are translucent and being to go stringy, add in a shake of dried thyme and/or a few springs of the fresh herb. After another minute or so splash in about 2 tbs balsamic vinegar and keep stirring. This whole process takes at least 20 minutes for the best effect. Finish with a small knob of butter for extra rich flavour.
4. When the onions are completely caramelised (a rich, translucent colour & soft, stringy texture) transfer them into a lidded mason jar and store in the fridge for up to a week.