Caramelizing onions isn’t difficult, but it does take a little practice to get them just right. Of course you can cheat a little by adding sugar or balsamic vinegar to add colour and sweetness, but that is not what this is about. This is about cooking onions that are not only dark and rich, but have a drier almost jam-like consistency that will help them last longer.
The following are tips I have learned from many years of making batches of caramelized onions in a restaurant setting where, of course, quality and consistency were always important.
Once you’ve mastered making really good caramelized on ions, you’ll want to have them on hand all the time. Keep a batch in a jar in the fridge or even pack them away in the freezer (they freeze pretty well because of the low water content). Besides these recipes, caramelized onions are great for burgers, quiche, steak sandwiches, pastas or anywhere you want to add a bit of sweetness.
Cut root to stem
Remove the root and stem ends, and the skins. Place the on- ions on a cutting board stem-side down and cut the onions in half. Orientate the onion halves so that the natural lines of the onions run towards you. Slice the onions from root to stem, along the “grain” or natural lines of the onion(cutting in this direction actually helps the slices retain their form and prevents water from weeping out too quickly), about 1/8-inch thick or as thinly as you can.
Resist the urge to stir
Once all the onions are cut, heat the largest pan you have over medium heat. This amount of onions is a lot for most pans (I used a 11.5-inch-wide pan). To avoid overcrowding the pan, you can cook the onions in stages. Add a tablespoon or two of oil to the pan and enough onions to cover the bottom of the pan. Season with a pinch of salt. Allow the onions to sit and cook on their own without stirring. Once the onions have started to brown on the bottom, give them a light fold (aggressively stirring will cause the onions to break up and release water too quickly.) Continue this process until the onions have softened, adjusting the heat if necessary to keep them from burning. If cooking in batches, remove the onions from the pan and place in a pot over medium-low heat and repeat the steps.
Cook until deep dark brown
Continue to cook the onions, slowly removing the majority of water while being very careful not to let them burn, adjusting the temperature if need be, folding only when necessary to keep them from burning.
Cook the onions until they turn rich, dark brown. This may take some time (about an hour), so go slow and be patient. It’s worth the extra time. Adjust the seasoning with salt if necessary and add thyme leaves, if you like. Once cooked, transfer the onions to a bowl to use right away. Any extra onions can be kept in a clean container in the refrigerator for up to seven days.
