Balsamic-Glazed Red Onions

Balsamic-Glazed Red Onions! Such an easy side dish. Great with roast chicken, Thanksgiving, or a vegetarian main dish.

  • Prep time: 15 minutes
  • Cook time: 1 hour, 10 minutes
  • Yield: Serves 4


For the onions:

  • 4 medium red onions (1 1/2 to 2 pounds total)
  • 2 tablespoons olive oil
  • 2 tablespoons balsamic vinegar (See our Guide to Balsamic Vinegar)
  • 1 tablespoon plus 1 teaspoon chopped fresh oregano
  • 1/8 teaspoon salt
  • 1/8 teaspoon ground black pepper

For the glaze:

  • 1 tablespoon balsamic vinegar
  • 1 teaspoon Dijon mustard
  • 2 tablespoons olive oil
  • 1/8 teaspoon salt
  • 1/8 teaspoon ground black pepper


1 Prepare the onions: Preheat the oven to 400F. Slice off any straggly roots from the onions, leaving the firm root centers intact. Cut the onions in half from tip to root. Peel off the skins until all the papery layers are removed. Cut each half into 4 wedges, slicing through the root so that the wedges stay intact.

2 Pack onions into baking dish: Pack the onions as tightly as you can into a 1 to 1 1/2 quart baking dish (9-inch round or oval, 8-inch square).

balsamic-onions-method-1 balsamic-onions-method-2

Sprinkle the olive oil, balsamic, 1 tablespoon of the oregano, salt, pepper evenly over the top. (No need to stir or you'll disturb the pretty arrangement!)

3 Roast the onions: Cover the baking dish with foil and roast the onions for 30 minutes. Remove the foil and continue roasting the onions uncovered for 30 minutes more.

4 Make the glaze: In a bowl, whisk the balsamic, mustard, salt, and pepper. Gradually whisk in the olive oil.

5 Pour the glaze over the roasted onions and return the dish to the oven. Continue cooking another 10 minutes, or until the onions are very tender when pierced with the tip of a knife.


6 Sprinkle the onions with the remaining 1 teaspoon oregano before serving.

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  • S.F Murray

    The best onion recipe ever. We grow lots of red onions and this recipe is the tops! Thanks

  • Kali

    Delicious! I will definitely make again. Thank you for this recipe.


  • Christina T

    This recipe is so simply perfect. I’ve never thought about cooking a dish of just onions and am so glad I came across this recipe. It is amazing! Thank you for sharing. I will be making this dish again and again!


  • David Jordan

    Thanks for the recipe I like onions.

  • whp

    Can one substitute shallots for red onions and, if so, how many (or how many pounds) and would you slice them or leave them whole? Thank you!

    • Sheryl Julian

      Hello whp! Shallots in this quantity would be too strong, but you can substitute sweet white onions, if you like. Happy cooking!

  • Peg Pierce

    Can these be made ahead of time and thenreheated, while the turkey is resting??

    • Sheryl Julian

      Hello Peg! Yes, make ahead but do not glaze. Reheat at 375 degrees for 20-30 minutes, or until hot. Then glaze and cook 15 minutes (it’s OK that the oven temp isn’t at 400 at this point). Happy cooking!

  • Natalie

    I love onions, you’re right they are far too often neglected. Slow cooked they’re just the best, such a great side for the autumn

    – Natalie