Balsamic Onion Marmalade

"This condiment of condiments is from Tom Colicchio and Sisha Ortuzar's book, wichcraft: Craft a Sandwich Into a Meal and a Meal Into a Sandwich. It is a simple twist on regular caramelized onions that manages to elevate the topping to a must-have. Yes, caramelizing onions takes a long time. So what? Do the time, do the crime (of eating deliciousness)! Since it keeps for several weeks, just make a batch and keep it on hand to dress up anything from sandwiches to salads. In the wichcraft book, it is used to make Roasted Turkey Sandwich with Avocado, Bacon, Onion Marmalade." It is also good on grilled hamburgers.

For a savory version of this made with bacon and balsamic vinegar, see Father's Office Burger from the Father's Office restaurant in Santa Monica. Chef Sang Yoon makes an Onion Compote to top off his burger that is named after the restaurant.

1 tablespoon vegetable oil
4 medium onions, thinly sliced (about 8 cups)
Kosher salt and freshly ground black pepper
1/3 cup sugar
2/3 cup balsamic vinegar

Heat the oil in a large skillet over medium heat until it slides easily across the pan. Add the onions, salt, and pepper and cook, stirring occasionally, for about 20 minutes, until the onions are soft.

Add the sugar and reduce the heat to medium-low. Cook the marmalade, stirring frequently, for about 10 minutes, until the onions appear dry. Add the vinegar and reduce the heat to low. Continue cooking, stirring occasionally, for about 1 hour, until the onions are soft and dry. Serve the marmalade warm or at room temperature. Store the marmalade in the refrigerator. It will keep for several weeks.