Recipe: Burger-Topping Onion Jam

After musing about practicing knife skills, a friend of mine suggested I make onion marmalade as a way to use up several pounds of onions after I would presumably dice them to practice more knife skills.

One look at the onion marmalade recipe, and I was sold. It is divine as a burger topping and just as good as a condiment on a cheese board with crusty bread.

Onions are my favorite vegetable, and jam (the version I spun out was much closer to a jam than a marmalade, a word that implies citrus to me) is by far my favorite condiment.

I ended up adding chili flakes to my version, but also scaling back the recipe significantly, wanting to try it once before committing to making a bigger batch. I also scaled it back because I remembered that of all the precision knife skills I want to practice, neither dicing nor thinly slicing onions are among them. In an average week, I easily chop, slice, or dice 2 pounds of onions. On the other hand, I really don't care for potatoes, so I have yet to Tourne a single one. I also need to work on the measurements of my julienne and brunoise cuts. But onions? I am masterful with onions and will happily keep a jar of this sweet and spicy jam on hand for burgers, sandwiches, and cheese boards for the rest of my life.

Burger-Topping Onion Jam
Makes about 1 1/2 cups, or two small jars' worth.
Note: This recipe can be doubled or quadrupled.

1 pound onions
1 tablespoon olive oil
1/2 cup dry red wine
1/2 cup white sugar
1/4 cup brown sugar
1/4 cup balsamic vinegar
1/2 teaspoon salt
1/4 teaspoon red chili flakes

1. Peel and either thinly slice or rough chop the onions. Rough chopping them will result in a chunky jam with more oniony zip, while thinly slicing them will yield a smoother and more mellow product.

2. Heat a large Dutch oven or heavy skillet over low to medium heat. Add the olive oil and onions, and stir to coat them. Partially cover the pot or skillet and be patient as they sweat. Stir the onions ever 5 minutes or so, until they are soft and perhaps beginning to brown just a little, about 15 to 20 minutes. If the onions have not browned at all, uncover them and raise the heat ever so slightly. You don't want to see any crisping or burning — just a color change.

3. Raise the heat to medium. Give the onions a few final tosses while the temperature inside the pan rises, then add the wine immediately and deglaze anything that may have stuck to the bottom of the pot.

4. Add the sugars, salt, vinegar, and chili flakes. Stir until the sugar has dissolved and the onions are well coated. Continue cooking, uncovered, until the liquid becomes syrup-like, bearing in mind that it will jell a bit more after it cools.

5. Leave the pot uncovered while the jam cools slightly, then transfer to sterilized jars (while the jam is cooking, drop the jars and lids into a pot of boiling water for a minute or too and then let them air dry). Store in the refrigerator.