I recently tried out a super hyped-up restaurant here in Chicago, not expecting much. I was surprisingly wrong and left wondering how on earth some of the flavors came together. My number one mission when I left was to attempt to reconstruct the onion jam and sage butter we had as an appetizer. My gosh was it amazing. Here's my attempt at what I found to be a delightful start to a meal.
In a large, thick bottomed pot, heat the butter and oil over medium heat. Add all the onion, garlic, rosemary, bay leaf, whole peppercorns and salt. Give the pot a good stir to make sure the onion is coated in oil and butter. Cover and let simmer for 20 minutes. Lower heat to medium low if anything looks like it is sticking to the bottom of the pan and burning.
Add the balsamic and red wine vinegars, white wine, honey and sugar. Add a bit more salt. Give the pot a good stir and let cook for 20 more minutes, uncovered. Stir the mixture occasionally to ensure nothing is burning. Adjust temperature as necessary.
Remove the rosemary sprigs and bay leaf. Some of the rosemary leaves will have fallen off, but don't worry, leave them in. The liquid should be reducing at this point. Cook for another 20 minutes (60 minutes total). Taste to see if salt should be adjusted.
Transfer the mixture to a food processor or blender and give a few quick pulses. You want to break up any rosemary leaves, and make the jam "spreadable", but not turn it into mush.
While the jam cooks, prepare your sage butter. Simply heat the butter, sage and salt over low heat. Let cook together for 10 minutes. Strain through cheesecloth into a small container and cool in fridge.
Serve the sage butter and onion jam together on any kind of bread you have! I used a big loaf of freshly baked, warm multi-grain bread to make the crostini.
The jam can also be sealed up and sent off as a wonderful holiday gift!