Method
- Heat the butter and oil in a wide heavy pan over medium heat. Add the onions and salt and toss to coat.
- Cook, stirring frequently, until the onions soften and release their moisture, 10–15 minutes.
- Reduce the heat to medium-low. Continue cooking for 35–50 minutes, stirring and scraping more often as the onions darken.
- Whenever the fond threatens to burn, add a tablespoon or two of water and scrape it back into the onions.
- Stop at an even deep amber color with a jammy texture. Adjust seasoning, then cool rapidly before storing.
Notes
A wide pan and patience create better flavor than added sugar. Deglaze the finished onions with wine, vinegar, or stock when a specific final use calls for it.
Related recipes and techniques
These are extensions, technique comparisons, or serving relationships; the complete recipe above remains usable as written.
- Use the onions as a topping on Cold-Fermented Pizza Dough.
- Press them into Rosemary Sea-Salt Focaccia before baking.
- Fold them into Baked Macaroni and Cheese for a sweet-savory variation.