Sweet Oven Roasted Red Onions with Balsamic

By Sally Cameron on February 17, 2015

Gluten-Free, the daniel plan, Vegan, Vegetables & Side Dishes, Vegetarian

Craving something sweet? As crazy as it sounds, just roast some onions. Sweet vegetables are a great way to fend off sugar and sweet cravings. Onions play a huge supporting role in recipes, giving wonderful flavor to many dishes. Instead of a supporting role, feature them as a side dish with these caramelized sweet red onions. You will be amazed a their rich sweetness.

Caramelized Sweet Red Onions |AFoodCentricLife.com

Sweet Oven Roasted Red Onions: Inexpensive and Healthy Side Dish

Searching of more ways to add vegetables to your dinner table? Consider the humble onion. Inexpensive and readily available, red onions are available year round in the produce department. Plus, onions are a non-starchy vegetable, so you can eat lots of them.

Red Onion Nutrition

Part of the allium family, which includes garlic, leeks, chives and scallions, onions are rich in sulfur-containing compounds that give them both their pungent odor and much of their helath benefits. Onions are a good source of vitamin C and B6, iron, folate, potassium and important plant chemicals called phytochemicals. These plant chemicals are good for our bones, our digestive systems, and may help fight diabetes, cancer and inflammation. Read more about the health benefits of onions in links at the end.

 What To Do With Onions: Roast Them

But what to do with my one onion languishing in my pantry? Roast it. For me, the first answer always seems to be roasting.  I cut up the onion and tossed it with olive oil, salt, pepper and my beloved granulated garlic that goes on everything. Into the oven went the onion, alongside a chicken roasting for dinner.

Sliced Red Onions|AFoodCentricLife.com

Roasting = Sweetness

The edges of the onion had turned a deep brown, even black in places, caramelized from the high heat of the oven. Roasting turns a normally pungent, eye-watering, mascara-smearing onion into something as sweet as candy. Yes, I see you looking at me with doubt and skepticism. Trust me. You must make these.

Sliced Red Onions|AFoodCentricLife.com

Balsamic & Thyme to Finish

As I pulled the casserole dish from the oven, the sweet smell wafted up to my nose, making me smile. I knew these were going to taste great. I tossed the onions with a little balsamic and fresh chopped thyme.

You can use either regular Balsamic vinegar or take it one step further. Make Balsamic syrup. This handy little condiment is always in a squeeze bottle by my stove for such uses. For how to make Balsamic syrup, read this post.

Caramelized Sweet Red Onions|AFoodCentricLife.com

How to Enjoy Sweet Oven Roasted Red Onions

  • Serve as a side dish along roast chicken
  • Pile on a grilled steak or steak salad
  • Pile them on asparagus for a double vegetable side
  • Add to a salad, either warm or cold
  • Pile on quinoa or rice with other vegetables for a delicious veggie bowl
Balsamic & Thyme to Finish and Serve|AFoodCentricLife.com
Balsamic & Thyme to Finish and Serve|AFoodCentricLife.com
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Sweet Oven Roasted Red Onions

The humble sweet red onion elevates to star staus with a little olive oil, balsamic, herbs and roasting. Serve aside chicken, beef, burgers or alone over a quinoa or rice bowl.
Course Side Dish
Cuisine American
Keyword onions, roast
Prep Time 10 minutes
Cook Time 40 minutes
Total Time 50 minutes
Servings 4
Calories 122kcal


  • 2 large red onions about 1 1/2 pounds
  • 3 tablespoons olive oil
  • 1/2 teaspoon sea salt
  • 1/4 teaspoon granulated garlic
  • 1/4 teaspoon ground black pepper
  • 1 1/2 tablespoons fresh chopped thyme leaves
  • 1-2 tablespoons Balsamic vinegar or syrup


  • Pre-heat the oven to 400°F. Ready a large glass or stoneware baking dish, about 10″x13″. Cut the onions in half from the top to bottom, from root to stem end.  Trim the root and stem ends flat. Peel off the papery skin, then lay each half flat on a cutting board and cut the halves into 6 wedges.
  • Add onion wedges to the baking dish and toss with oil, then sprinkle with salt, pepper and garlic. Roast onions uncovered for about 40 minutes, or until they are very soft and the edges are very brown, even a little black in places. Remove dish from the oven, toss with the Balsamic and sprinkle with thyme leaves.


Calories: 122kcal | Carbohydrates: 7g | Protein: 1g | Fat: 11g | Saturated Fat: 1g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Sodium: 294mg | Potassium: 105mg | Fiber: 1g | Sugar: 3g | Vitamin A: 127IU | Vitamin C: 8mg | Calcium: 25mg | Iron: 1mg

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