Skip to Content

Roasted Onions

  • Serves: 6
  • Prep Time:  5 min
  • Cook Time:  35 min
  • Calories: 128
roasted onions on a plate made with olive oil, red wine vinegar, lemon juice, dijon, spices and brown sugar
Photography by Gayle McLeod

Oven roasted onions in a delicious blend of spices turn tender, sweet, and slightly charred when cooked in a hot oven. Serve them as a side for a super cozy dinner.

Roast An Onion, Fall In Love

Caramelized Onions, Pickled Onions, and now roasted, we love onions for their versatility in every iteration. Oven roasting onions gives them an unexpected flavor profile (sweet and mild) and a really gorgeous texture. We serve these alongside some of our favorite pork dishes like this easy Apricot Pork Chop Sheet Pan Dinner or flavorful Grilled Pork Tenderloin with Chimichurri. These roasted onions also love a good steak, and this Grilled Five Spice Flank Steak is a real winning combination with a side of Roasted Garlic Mashed Potatoes.

Oven Roasted Onions Deliver Major Flavor And Texture

Roasting vegetables elevates vegetables to a magical level by transforming taste and texture, and onions roasted in a hot oven are no exception. Our tips for roasting any vegetable applies to roasting onions as well. Starting with a hot hot oven (425° F for this recipe), and making sure to give the onion wedges space on the pan, so they roast and not steam (we’ve said it before and we’ll say it again!) will take these roasted onions deep into roasted flavor goodness.

raw red and yellow onions cut into large wedges to make roasted onions

How To Roast Onions

  • Start with two large onions. Which onions are best for roasting? We recommend using yellow or red, because they hold up well during the roast. How do you cut an onion for roasting? We trim and peel the onions, and cut them into wedges for this preparation.

  • Make the dressing for the onions by whisking the oil, vinegar, lemon juice, mustard, salt, pepper, garlic powder, onion powder, thyme and brown sugar together in a large bowl.

  • Put the onion wedges on a baking sheet, and drizzle with the dressing, reserving what’s left in the bowl for service.

  • Roast the onions in an oven set to high heat (crank up the oven to 425° F), to bring out the natural sweetness of the onions and give them a nice char.

  • How long to roast onions: Cook the onions for about 35 minutes, stirring every ten minutes or so.

  • When you pull the onions out of the oven, drizzle with the remaining dressing and serve these roasted sliced onions warm.

raw onion wedges tossed with  olive oil, red wine vinegar, lemon juice, dijon, spices and brown sugar ready for roasting
roasted onions on a baking sheet made with olive oil, red wine vinegar, lemon juice, dijon, spices and brown sugar

Tools You’ll Need

Let’s Peel The Onion

Onions show up in so many recipes, frequently as a base to build flavor with garlic and spices, but they’re just as good when they show up as the star of the show. Here’s a few of our favorite that give onions their shine:

roasted onions on a plate made with olive oil, red wine vinegar, lemon juice, dijon, spices and brown sugar

Is Someone Cutting Onions?

We get emotional when we think about how these delicious roasted onions are. We’d love to see your beautiful roasted onions on the dining table and maybe even a video of the beautiful people you feed it to. Tag us on Instagram using @themodernproper and #themodernproper. Happy eating!

Roasted Onions

  • Serves: 6
  • Prep Time:  5 min
  • Cook Time:  35 min
  • Calories: 128

Ingredients

  • ⅓ cup extra-virgin olive oil
  • 1 tablespoon red wine vinegar, white wine vinegar, or sherry vinegar
  • 1 tablespoon fresh lemon juice (from 1 lemon)
  • 1 teaspoon Dijon mustard
  • 1 teaspoon sea salt, plus more for serving
  • ¼ teaspoon freshly cracked black pepper
  • 1 teaspoon garlic powder
  • ½ teaspoon onion powder
  • ½ teaspoon dried thyme
  • 1 teaspoon brown sugar
  • 2 large yellow or red onions, halved and cut into 3/4-inch-thick wedges

Method

  1. Preheat the oven to 425°F with a rack in the center position.

  2. In a large bowl, whisk together the oil, vinegar, lemon juice, mustard, salt, pepper, garlic powder, onion powder, thyme, and brown sugar.

  3. Add the onions to the bowl with dressing and toss until wedges are separated and well coated.

  4. Using a slotted spoon, transfer the onions to a rimmed sheet pan, reserving the leftover dressing in the bowl.

  5. Roast the onions, stirring every 10 minutes, until tender and lightly charred, about 35 minutes.

  6. Drizzle the onions with the reserved dressing and toss to combine. Season with salt.

Nutrition Info

  • Per Serving
  • Amount
  • Calories128
  • Protein1 g
  • Carbohydrates6 g
  • Total Fat12 g
  • Dietary Fiber1 g
  • Cholesterol0 mg
  • sodium409 mg
  • Total Sugars3 g

Roasted Onions

Questions & Reviews

Join the discussion below.

or

    Any questions?

    Need to change up some ingredients? Unsure about a step in the method? Click the Ask a Question button above. We’re here for you.

  • Jenn

    Fabulous. I'll be eating these on EVERYTHING!

    Yay! Glad you love them!