These Roasted Onions with Thyme are an ideal side dish, easy enough for weeknight meals as well as being a perfect addition to your festive table. The simple process of roasting the onions totally transforms them; as they cook, their sugars caramelise, enhancing their natural sweetness. And they are so easy to make! Just add the trimmed, halved onions to a baking dish along with some olive oil, season with salt, pepper and sprigs of thyme then roast. A drizzle of sweet, yet tart, Balsamic Glaze just before serving takes this side dish to new heights.
You will love these Roasted Onions with Thyme because:
- This is a healthy side dish that is easy to make and full of flavour, as well as being budget-friendly.
- You can transform an everyday ingredient into a full-flavoured side dish which will be ideal to serve with meat, fish or poultry such as our Spatchcock Chicken. As well, they are a great addition to salads, added to a sandwich or wrap or served at a barbecue.
- The Roasted Onions are naturally gluten-free and vegan, making them suitable for many people with specific dietary requirements.
- Whether you are cooking for a large or small number of people, you can scale this recipe up or down, depending on your requirements.
Ingredients in this recipe:
Please see the recipe card further along in the post for exact quantities of ingredients and the full method.
Brown/yellow and red onions – we use two varieties for the colour variation, but you can use any onion that you prefer. The red onion is sweeter than the brown/yellow or white onion.
Extra virgin olive oil – this is our preference for flavour and nutritional benefit. Use the best olive oil that you have.
Fresh thyme – a few sprigs of this aromatic, fresh herb add great flavour to the onions.
Sea salt and freshly ground black pepper – add to suit your taste.
Balsamic glaze – optional, but is fantastic when serving. It adds a sweet, tart flavour that perfectly complements the Roasted Onions.
How to Roast Onions:
Please see the recipe card further along in the post for exact quantities of ingredients and the full method.
1 – Place your onions in a baking dish:
Preheat your oven to 200 degrees C (390 F).
Cut the onions in half lengthways, and peel. Trim the stem end and leave the root intact to hold the onion halves together.
In a small cast iron skillet or baking dish, place the onions cut side up and drizzle with the olive oil. Top with the sprigs of thyme and season with salt and pepper.
2 – Roast until tender:
Roast for 35 minutes, turning the onions over halfway through to ensure even cooking.
Remove from the oven when they are tender. Arrange on a serving platter and drizzle with balsamic glaze.
Tips for success and FAQs:
When a recipe has so few ingredients, it is essential that they be of the best quality. Choose onions that are heavy in your hand, firm, with dry, papery skins and free of blemishes. Avoid any with soft spots, signs of sprouting or a strong odour. For the best appearance and even cooking, choose onions of a similar size.
Store leftover Roasted Onions in an airtight container in the fridge for up to 3 days. The onions are at their best when fresh from the oven, but leftovers can be added to salads, soups, stews or burgers.
You certainly can, they are ideal for meal prep. To get ahead, prepare the onions a day ahead of time and store in an airtight container in the fridge overnight.
What variety of onion is best to use?
You can use most onions for roasting. Here’s a little information on some suitable varieties to use:
Brown/yellow onions – this is the most versatile onion and the variety most used as an all-rounder. This variety includes globe onions and the slightly sweeter Spanish onions.
White onions – this variety is named for its white flesh and thin white skin. Their flavour is milder than brown or red onions.
Red onions – also known as purple onions, they are sweeter than brown/yellow and white onions.
Sweet onions – these onions have a mild flavour. They have a lower sulphur content which makes their sugar content more noticeable. Popular varieties are Vidalias, Walla Wallas and Mauis.
Cipollini – this is an Italian heirloom onion variety. Their name, in Italian, means “little onion”. Cipollini is a more uncommon variety of onion, but they are worth seeking out. The onions are a flat, saucer shape with thin, papery skins. These onions contain more natural sugar than regular white or brown onions, and as such, when roasted they caramelise beautifully.
Serving suggestions:
These Roasted Onions are a great addition to a barbecued steak, hamburger, or any roast meal, along with my Whole Roasted Baby Potatoes or Roasted Tenderstem Broccoli.
As well, for a light meal or vegetarian appetiser, serve the Roasted Onions on a bed of rocket, drizzled with Balsamic Glaze and scattered with some fresh goat cheese or feta. The mild acidity of the cheese beautifully complements the sweetness of the onions.
They also make a delicious appetiser. Make some Crostini, spread them with soft goat cheese and top with some onion and a sprinkle of fresh thyme leaves.
This easily made dish of Roasted Onions is a must for all onion lovers. With just a few simple ingredients, the humble onion is transformed into a side dish which is a guaranteed crowd-pleaser. I look forward to hearing if you try it.
Alex xx
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Roasted Onions with Thyme
Please note:
For accuracy, when weights are provided, we recommend weighing your ingredients. This will produce the best results. All oven temperatures listed are for fan forced.
Ingredients
- 2 brown/yellow onions See Note 1
- 2 red onions
- 3 tablespoon extra virgin olive oil See Note 2
- 8 stalks fresh thyme
- sea salt and black pepper – to taste
To serve (optional):
- balsamic glaze See Note 3
- rocket/arugula leaves
Instructions
- Preheat oven to 200 Degrees C (390 F).
- Cut the onions in half, remove the stem and peel. Leave the root intact to hold the onion half in place.
- In a small cast iron skillet or baking dish, place the onions cut side up, and drizzle with the olive oil. Distribute the thyme over and around the onions and sprinkle with salt and pepper.
- Roast for 35 minutes, turning over halfway through to ensure even cooking.Remove from oven when they are tender and cooked through – check with the point of a sharp knife.The exact roasting time will vary depending on the size of your onions.
- Serve as is, or with a drizzle of balsamic glaze.
Notes
- Onions: I have used a combination of brown/yellow and red onions. Cipollini onions also work well and can be roasted whole.
- Tablespoon: we use a standard Australian tablespoon which is 20 ml (4 teaspoons).
- Balsamic glaze: use store-bought or make your own.
Nutrition Estimate:
Nutritional Disclaimer:
The nutritional information is an estimate only, and is derived from online calculators. For accurate results, we recommend calculating the nutritional information based on the ingredients and brands you use.
This post was originally published in October 2018. It has been updated with new photos and more information. The recipe has been altered slightly.
Margaret
Made these to serve over the holidays and was asked for the recipe twice! They turned out perfect and were so easy, yet elegant looking on the table. Will make again soon!
Alexandra
Hi Margaret, I am so pleased to hear that you enjoyed the Roasted Onions with Thyme and will make them again soon. Thank you for taking the time to let me know. 🙂
Patricia A Giza
love this recipe. Simple and ea
Alexandra
Thank you, Patricia!
Anne
These roasted onions came out perfectly sweet and caramelized! I used cipollini onions and pearl red onions for their color. I highly recommend the balsamic glaze – it’s a game changer! We served them with your spatchcock chicken and my family loved it!
Alexandra
Hi Anne, I am delighted to hear that you enjoyed the Roasted Onions served with our Spatchcock Chicken. Thank you for your lovely comments. 🙂
Emma
These were my first time trying cipollini onions and it won’t be my last! It’s definitely sweeter and great for roasting. My family loved it with our roast chicken dinner tonight!
Alexandra
Hello Emma, I am so pleased to hear that you and your family enjoyed the Roasted Cipollini Onions. They would have been a delicious addition to your roast chicken. 🙂
Abigail
I made these last night to go alongside some grilled steak and it was incredible! The onions turned out so sweet and perfectly roasted. Definitely don’t skip the balsamic vinegar at the end! It was delicious!
Alexandra
Thank you Abigail for the fantastic feedback! I am delighted to hear how much you enjoyed the Roasted Onions; and yes, the Balsamic adds a special touch. 🙂
twinspirationalparties
This recipe is perfect!
Alexandra
Thank you so much!
Bree
These Roasted onions are seriously SOOOOOO GOOOOOD!!!
Alexandra
I am so happy to hear that Bree. Have a great weekend. 🙂
Amy-Lynn Denham
Anything with roasted or caramelized onions and you got my mouth WATERING!
Alexandra
I absolutely agree; always a winner. 🙂
Cristina Petrini
Everything that is roasted, grilled and baked makes me so happy! Especially vegetables! This recipe is lovely.
Alexandra
Me too Cristina! Hope you enjoy! 🙂
Christina
Sooooo yummy! And with goat cheese – DELICIOUS! Thank you for sharing.
Alexandra
My pleasure, Christina! Enjoy!! 🙂
Evelyn Hernandez
We love roasting onions, it caramelizes them and they taste so sweet! Love this recipe!
Alexandra
Thank you, Evelyn 🙂 So glad you agree!
gemma redford
Oh my goodness, these are so yummy! And easy to make! great recipe 🙂
Alexandra
Thank you, Gemma! Appreciate you stopping by 🙂
Yeah Lifestyle
These are incredibly delicious and make the perfect side. I love thyme, its a great herb to use in dishes.
Alexandra
Thanks so much – I agree, love thyme! Enjoy 🙂
Chad
I can’t thank you enough for this awesome recipe! It turned out to be DELICIOUS!!!
Alexandra
Hello Chad, thank you so much! So glad you enjoyed it 🙂
Brian
A perfect side dish. Delicious.
Alexandra
Fantastic – thank you so much, Brian. Enjoy! 🙂