This jam is a gift of time but very little effort, and the payoff is an irresistible condiment that will elevate cheese and crackers, a plain sandwich, or a burger into a gourmet occasion. This recipe maximizes caramelization of the natural sugar in onions and enhances it with a sweet-tart touch of brown sugar and balsamic vinegar.
Ingredients to start with
- 3 pounds onions, peeled and cut into 1/4-inch dice (I generally use yellow onions but any round onions will work)
- 3-4 tablespoons extra virgin olive oil
- 1/2 teaspoon kosher salt (or 1/4–1/3 teaspoon table salt)
- 1/2 teaspoon dried thyme
- 1/2 teaspoon dried oregano
- 6 cloves garlic, chopped
Ingredients to add
- 3 tablespoons brown sugar (packed)
- 5 tablespoons balsamic vinegar
Preparation
- In a large pot, heat olive oil on medium heat and add diced onions. Add salt, herbs and garlic, and stir. Cover pot and turn down heat to medium-low. Cook for 15–20 minutes. The heat and steam will help the onions break down.
- Uncover pot and turn heat to low. Cook uncovered for an hour or so, stirring every once in a while with a spatula, scraping the pot during stirring as the onions continue to shrink down and brown.
- Our goal here is a very soft, deep brown onion mixture, with just enough heat to cook the onions but not so hot that the mixture burns. If your low heat setting still seems high, you can add a tablespoon of water when you stir it, or partially cover the pot with the lid to retain some steam. Too much water will keep the mixture from browning, which is where the caramelization happens.
- At the end, you want the onions to be very soft, with some pieces falling apart into a soft sludge (generally I wrap it up when I run out of patience or time). Add brown sugar and balsamic vinegar to the pot. Stir to mix. Cook another 5 minutes or so, adjusting to taste. The balsamic vinegar I use is fairly sweet to begin with, so if yours is more tart, you might need more sugar to balance the acidity (see Notes).
- This recipe makes about three 8-ounce jars. Onions have naturally antibacterial properties, so the jam will keep well unopened in the refrigerator for a couple of months. It’s fantastic with cheese and crackers on a charcuterie board, as a spread on a sandwich or on the side with a protein dish.
Notes
- Adjust vinegar and sugar to taste. I use an organic balsamic vinegar from Costco that is thick and sweet. You may need to add 1-2 additional tablespoons of sugar if your balsamic vinegar is runnier and more tart.
- Herbs are flexible here — use thyme or oregano if you only have one. Rosemary would also be good.
- You can also use granulated sugar if you don’t have brown.
- Once in use, always use a clean utensil with the jam to avoid introducing bacteria to the jar. This will keep the jam fresh for longer.
Here’s a link back to the post and pictures.
