Balsamic-Glazed Red Onions

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

By
Sheryl Julian
Sheryl Julian
Sheryl Julian
Sheryl Julian was the Food Editor, reporter, stylist, and recipe developer for The Boston Globe for 30 years. She teaches food journalism at Boston University in the Masters in Gastronomy program.
Learn about Simply Recipes' Editorial Process
Updated March 10, 2022
Sheryl Julian
Balsamic Onions
Elise Bauer

Onions are too often the supporting actors in the kitchen when they should be the stars.

This stunning dish gives red onions their own glamorous role at the table. Roasted and glazed with balsamic vinegar, these onions can accompany a vegetarian main course or a succulent roast chicken without skipping a beat.

Even better: the recipe is so simple that you’ll think you’re cheating.

When you're prepping the onions for this dish, peel until there's no papery skin left. Also keep the roots intact by barely trimming them so that the onion wedges stay joined during roasting.

Pack the onion wedges tightly into your baking dish – really jam them in – and sprinkle with olive oil, balsamic, and fresh oregano, or whatever other herb you have on hand.

Roast them for a whole hour – don’t skimp on the timing. The finished onions should be practically melting by the time they're done.

The last pièce de résistance is a balsamic-Dijon glaze poured over top the nearly-finished onions. Send the onions back to the oven briefly, then sprinkle with a little extra oregano and present your new starring dish to the table.

Balsamic-Glazed Red Onions

Prep Time 15 mins
Cook Time 70 mins
Total Time 85 mins
Servings 4 servings

Ingredients

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

Method

  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).

    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!)

    balsamic-onions-method-1
    Elise Bauer
    balsamic-onions-method-2
    Elise Bauer
  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.

    balsamic-onions-method-3
    Elise Bauer
  6. Serve:

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

Balsamic Onions
Elise Bauer
Nutrition Facts (per serving)
173 Calories
14g Fat
12g Carbs
1g Protein
×
Nutrition Facts
Servings: 4
Amount per serving
Calories 173
% Daily Value*
Total Fat 14g 18%
Saturated Fat 2g 10%
Cholesterol 0mg 0%
Sodium 167mg 7%
Total Carbohydrate 12g 4%
Dietary Fiber 2g 5%
Total Sugars 6g
Protein 1g
Vitamin C 6mg 31%
Calcium 29mg 2%
Iron 1mg 3%
Potassium 178mg 4%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.