Whole Roasted Onions In Foil
Last Updated on September 10, 2020 by Betty Davies
Onions have never tasted so good! These whole roasted onions are wrapped in foil to be cooked and the result is the most buttery side dish that is loaded with flavor. So quick and easy to prep and just a few ingredients needed. Vegetarian and gluten-free.
Onions are one of my favorite vegetables, but rather than using them to add flavor to the dish, with this recipe they can be a side in their own right!
They are super delicious and come out perfectly buttery, tender and full of flavor. They are fancy enough to serve to company on special occasions, but simple enough to make you can enjoy them as part of a weeknight family meal.
Why you will love these roasted onions!
- Hands off: It takes no more than 5 minutes of prep time and the cook time is totally hands off, leaving you to get on with other things.
- Simple ingredients: Nothing fancy here, you can whip up these onions without needing a special trip to the store.
- Easy: This side is so easy you have to give it a try! You don’t even have to peel the onions!
Ingredients
- Onions: For this recipe I used sweet onions (Vidalia), but you can easily use red or yellow onions instead.
- Oil: I like to roast with olive oil as that rich flavor seeps into each bite. You can use neutral oils like grapeseed or canola, but you won’t get that extra bit of flavor.
- Butter: I prefer to use salted butter. If you use unsalted, just add a pinch of salt to the top of each onion.
- Thyme and Rosemary: Fresh thyme and rosemary add a wonderful subtle herby and earthy flavor. If you are in a pinch, you can use dried herbs.
How to roast whole onions in foil
Be sure to scroll down for the full recipe!
- Cut the tops and bottoms off of the onions.
- Place on foil, drizzle with oil and top with butter and herbs (photo 1).
- Wrap in foil and roast until they are soft and buttery (photo 2).
Recipe Variations
These whole roasted onions are pretty awesome as they are, but you can easily make them to your taste:
- Mix up the herbs. Sage, oregano and tarragon will all work well.
- Make it vegan by omitting the butter or using a diary-free brand.
- Add a couple of crushed garlic cloves for an extra hit of extra flavor.
- Add some chili flakes if you like a bit of heat.
- Drizzle over some balsamic vinegar.
Frequently Asked Questions
It will take around an hour for the onions to roast, but of course, this will depend on the size of the onions you are using. I used pretty large onions and they took just over an hour, if you are using smaller ones, give them a check after 50 minutes.
These onions are best served soon after you’ve roasted them so that they don’t dry out. You can leave them wrapped in the foil up to an hour before you want to serve them to keep them warm. If you want to reheat them, just keep them wrapped in foil and place in the oven at 350F / 180c for 10 to 15 minutes to warm through.
No! You just need to top and tail the onions, be sure to keep that skin on! The skin protects the flesh of the onion and helps to keep the moisture in. When you are ready to serve just remove the skin, which will come off pretty easily.
Serving Suggestions
These onions will work pretty well with most meals, but here are my favorite options:
- Roasted Chicken
- Roasted Beef
- Burger topping
- Hot dog topping
- Warm salads
- Onion gravy
Recipe Notes and Tips
- Do not remove the skin of the onions, it will help protect the flesh from the heat.
- Don’t wrap the foil too tightly. Tent it to let the air circulate.
- Cooking times will vary depending on the size of your onions.
- The onions are done when they are fork tender.
More Easy Side Dish Recipes
- Spinach Orzo Pasta Salad
- Homemade Easy Cheesy Garlic Bread
- Lemon Basil Pesto
- Crispy Fried Potato Slices
If you’ve tried this recipe, be sure to leave a star rating and a comment below!
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Whole Roasted Onions In Foil
Ingredients
- 2 large onions
- 2 tablespoons oil
- 2 tablespoons butter
- 6 sprigs thyme
- 4 sprigs rosemary
- black pepper and fresh parsley to serve (optional)
Instructions
- Pre heat the oven to 460F / 240c.
- Cut the tops and bottoms off of the onions and lay them on separate sheets of foil, cut side up.
- Pour a tablespoon of oil on top of each onion, and then a tablespoon of butter on top.
- Sprinkle some fresh thyme and rosemary leaves on top of each onion and place the left over sprigs around the base.
- Wrap the foil around the onions. Tent it so that they are not super tightly wrapped to let the air circulate.
- Place in the oven for an hour until they are soft and buttery.
- Brush off the roasted herbs, remove the skins and sprinkle with some freshly ground black pepper and some fresh parsley.
Notes
- Do not remove the skin of the onions, it will help protect the flesh from the heat.
- Don’t wrap the foil too tightly. Tent it to let the air circulate.
- Cooking times will vary depending on the size of your onions.
- The onions are done when they are fork tender.
Hi Betty,
Just came across your website thank you.
Like yourself I love onions but began to experiment with them over the past 10 days or so and your comments were helpful.
While in the USA I came across a full sized onion thinly sliced but not separated and roasted. It was the most delicious onion I ever tasted. I tried cooking this myself but it was nothing like I was served in the restaurant. Have you come across this type of roasted onion, tried all the internet but failed to get any advice on it. Thank you Betty, have a lovely day. Sean
Hi Sean! You have me a bit stumped on this one I’m afraid! The only thing I can think of is a blooming onion, though they do tend to be deep fried rather than roasted, though I did find this oven baked one https://www.delish.com/cooking/recipe-ideas/recipes/a53841/baked-bloomin-onion-recipe/ I don’t think that’s what you had as these have a breading on them. Would love to know if you do find out what you had!!
OMG!! Did these today on the bbq with prime rib of beef…… Absolutely delicious, wish there were more words to describe how amazingly scrumptious these are. Turns a humble onion into a truly regal accompaniment to this choice cut of beef. Wow!
So glad you enjoyed them Dawnie! Thanks for the lovely comment 🙂
So good! I tried it and it turned out superb so easy to make.
Hi Amita! So glad you enjoyed them! Thanks for taking the time to comment!
Love this idea! So simple but so delicious! Now that the weather is warming up, we can imagine how delicious your roasted onions would go so well with so many fall cozy recipes.