Caramelized Onion Jam

Melt the butter in a wide, heavy-bottomed skillet or Dutch oven over medium heat. Add all the sliced onions, salt, and thyme at once. The pan will appear overfull — this is correct, they reduce dramatically. Stir to coat in butter, then cook undisturbed for 5 minutes until the bottom layer begins to soften and turn translucent. The salt draws moisture immediately, which will build into a gentle steam. Stir every 3–4 minutes.

Reduce heat to medium-low. From this point, the process takes 45–60 minutes and cannot be hurried. Stir every 5 minutes, scraping up any fond developing on the pan bottom. Do not add liquid unless the onions are sticking and threatening to burn — the moisture from the onions themselves is sufficient. At the 20-minute mark the onions will be golden; at 40 minutes, amber; at 60 minutes, a deep mahogany. The aroma shifts from raw sweetness to something deeply complex — caramel, savory, and almost meaty from the Maillard reaction.

Pour in the wine and stir vigorously, scraping up all the fond from the pan bottom — this is concentrated flavor. Add the brown sugar and balsamic vinegar. Increase heat to medium and cook for another 5–8 minutes, stirring frequently, until the liquid has reduced almost completely and the mixture is thick, glossy, and jammy. Remove the thyme sprigs. Taste and adjust: more balsamic for tartness, more sugar for sweetness, a pinch more salt if flat.