Balsamic Roasted Onions are an elegant side dish to any meal. Presented whole, they are caramelized, soft, and sweet. You can also use larger onions and quarter them, or even use pearl onions.

Baking dish of Balsamic Roasted Onions on a wooden tray with silverware beside on a napkin

What kind of onion should I use?

You can use small-medium sweet onions, and I love to use flat Italian cipollinis. In season, Southerners should seek out Vidalia onions, Northwesterners should look for Walla Wallas, Texans should use Texas Sweet onions, and Hawaiians shouldn't deter from Maui Sweets! If the onions are large, you can cut them into quarters. For an appetizer version of this recipe, use pearl onions and offer toothpicks or roast them on skewers.

A blue and white bowl with onions piled in it.

Want to learn a little about these onions?

Walla Walla Onions are from the Walla Walla Valley in Washington State, USA, and are lovingly referred as the Washington State Vegetable. This onion came to WA via the island of Corsica, where a French soldier found the onion seeds and brought them to WA when he immigrated in the late 1800s. The onions are sweet due to the low amounts of sulfur in the soil and are harvested by hand. A Walla Walla onion can only be called that if it was grown in the Walla Walla Valley.
Vidalia onions are a type of sweet onion that originated in Toombs County, Georgia, and are exclusively grown within 20 counties in South Georgia. Similar to Walla Walla onions, they come from soil with low sulfur levels lending to their sweetness. Unlike Walla Walla onions, they are more flat rather than round.
Like Walla Wallas and Vidalias, Maui onions are distinctively sweet, lacking the sulfur that gives most other onions their sharp taste and tear-producing odor. The onions also have a high water content resulting in a gorgeous juiciness. They are, obviously, grown on the island of Maui although farmers across the islands try to replicate the crop in their own soil.
The first sweet onion came to Texas from the Bermuda Islands. The onions became so popular that the farmers couldn't keep up the demand for seeds. Texas A&M stepped in and created an onion breeding program to propagate Texas Sweet Onions. Of course, being Texans, they claim that all other sweet onions started with them!

Let's get started

Start by preparing the onions. Peel and trim them. If you are using a larger onion, cut them into quarters. Season them with salt and pepper.

Peeled whole onions in a baking dish, paring knife laying beside, and more onions in a bowl.

Heat a skillet over medium high heat and sear the cut sides of the onions.

Browned whole onions in a cast iron skillet

If you have an oven-proof skillet, pour the balsamic vinegar right into the skillet. If you are using a baking dish, place the seared onions in it, then pour the balsamic vinegar over. You just want to coat the bottom of the pan or baking dish.

A word of warning

Balsamic vinegar is prone to burning because of the sugar content so keep an eye on the baking dish in the oven! Turn the oven down if you need to and add a bit more vinegar if the onions aren't yet cooked through.

Browned onions in the baking dish with balsamic vinegar drizzled over.

How to serve

These onions pair so well with grilled or roasted meats like steak, pork chops, and roasted chicken. And while the oven is on, you might as well roast some potatoes or sweet potatoes to round out the meal. Right? Roasted Balsamic Onions are also delicious with sautéed spinach or chard. YUM!

Balsamic Roasted Onions on a wooden tray with vintage silverware on a linen napkin

Recipe

Balsamic Roasted Onions

Tammy Circeo

Roasted Balsamic Onions are an elegant side dish to any meal. Presented whole, they are caramelized, soft, and sweet.

5 from 1 vote

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Prep Time 15

Cook Time 30

Total Time 45

Course Appetizer, Side Dish

Cuisine American

Servings 6 servings

Ingredients

6 medium onions See notes for onion choice
Salt & Pepper to taste
2-3 Tablespoons olive oil
⅓-½ cup balsamic vinegar

Instructions

Heat oven to 450℉.
Peel and trim onions. Season with salt & pepper. Heat olive oil in an oven-proof skillet over medium high heat. Sear the onions on both cut ends. If you don't have an oven-proof skillet, transfer the onions to baking dish.
Turn off the heat and add as much balsamic vinegar as will cover the bottom of the pan or baking dish.
Place the skillet into the oven, uncovered, and roast until the onions are tender, about 45 minutes to an hour (unless you are using tiny onions, in which case, you should check them sooner). The tip of a knife should poke through with no crunchiness.

Notes

For an appetizer version, use pearl onions and offer toothpicks or skewers.

Keep an eye on the balsamic vinegar. It will reach a point where it is thick and syrupy and can easily burn at that stage. This is another reason to use smaller onions or to cut larger onions into smaller pieces.

While the oven is on, you might as well roast some potatoes or sweet potatoes to round out the meal. Right? Roasted Balsamic Onions are also delicious with sautéed spinach or chard. YUM!

Keyword balsamic roasted onions, balsamic vinegar, onions, roasted onions

Yum