Yields 2 cups

Preparation time: 30 minutes


• 1 tablespoon unsalted butter

• 1 teaspoon extra-virgin olive oil

• 2 Spanish onions - thinly sliced (about 2 cups)

• 1⁄2 cup water

• 1 teaspoon brown sugar

• 1 tablespoon balsamic vinegar

• Kosher salt

• Cracked black pepper


  1. Heat the butter and olive oil in a large skillet over low heat until butter melts

  2. Add the onions and sauté for 5-10 minutes, until beginning to brown

  3. Add the water and continue sautéing until nearly caramelized and water is evaporated

  4. Add the sugar and vinegar and continue sautéing until the vinegar is completely reduced

  5. Salt and pepper to taste

  6. Transfer to an airtight container and refrigerate. May be made ahead and will keep for up to one week