Recipe information
Yield
makes 2 to 3 cups
Ingredients
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
Preparation
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, 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 warm or at room temperature. Store the marmalade in the refrigerator. It will keep for several weeks.
