Roasted Vidalia Onions
Roasted Vidalia Onions are a delicious side dish idea, and Parmesan Cheese bumps up the flavor in this recipe! Vidalias and other types of sweet onions are higher in carbs than most onions, but if you use portion control this isn’t too huge of a splurge on carbs.
PIN Roasted Vidalia Onions to try them later!
Roasted Vidalia Onions were so easy and delicious, and there’s nothing I love more than an ultra-easy recipe that produces a truly memorable dish. And Vidalia onions are not something I’ve cooked with much, but I recently bought a big bag of as part of a fundraiser, so I’ve been thinking of ways to use them.
I used a few onions in a Greek salad where I marinated the onions, and then I had the idea of marinating and then roasting the onions. If you’re a fan of caramelized onions, this dish has that same umami-laden flavor.
Next time you’re cooking something in the oven, try marinating and then roasting some Vidalia Onions or other sweet onions for a delicious side dish!
What ingredients do you need?
(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)
- Vidalia onions
- Balsamic Vinegar (affiliate link)
- Spike Seasoning (affiliate link), or other all-purpose seasoning blend
- Dried Thyme (affiliate link)
- Olive Oil (affiliate link)
- freshly grated Parmesan cheese
- salt and fresh ground black pepper to taste
What are Vidalia Onions?
Vidalia onions come from Vidalia, Georgia, where the low sulfur soil produces sweet onions with a mild flavor. Only onions from Georgia can be called Vidalia onions, and the name is trademark-protected. If you can find Vidalia onions in your store they are really tasty!
What other types of Sweet Onions could you use?
If you don’t find Vidalia onions in your store, you could make this recipe for roasted onions with Maui Onions, Texas Sweets, or Walla Walla Sweets.
How low in carbs are the Roasted Vidalia Onions?
This recipe for marinated and roasted onions served with Parmesan has about 14.9 net carbs per serving.
How to Make Roasted Vidalia Onions:
(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)
- Vidalia onions are white with a slightly golden skin, and usually they’re sold when they’re just medium-sized.
- After peeling, I sliced the onions into slices about 1/2 inches thick Try to make all the onions slices the same thickness, and separate onions into rings after slicing.
- Whisk together balsamic vinegar, olive oil, Spike Seasoning, and dried thyme, and marinate onions for 4 hours or longer.
- Let marinated onions drain well while you preheat the oven to 400 F.
- When oven is hot, arrange onions on a baking dish.
- Roast onions for 30-40 minutes, turning every 10 minutes, or until onions are well-browned, especially on the edges. (I was cooking this in my toaster oven or I would have spread them out on the pan a bit more.)
- Serve the Roasted Vidalia Onions hot, with a sprinkling of grated Parmesan as desired.
More Recipes with Sweet Onions:
- Asian Cucumber Salad
- Green Tomato Salsa with Avocado
- Middle Eastern Tomato Salad
- Grilled Halloumi Cheese with Mushrooms
- Easy Grilled Vegetables
Roasted Vidalia Onions
Roasted Vidalia Onions are a delicious side dish idea for everyone who likes sweet onions.
Ingredients
- 4 medium-sized Vidalia onions (see notes)
- 2 T balsamic vinegar
- 1/4 tsp. Spike Seasoning (see notes)
- 1/4 tsp. dried thyme
- 1/4 cup olive oil
- 2 T freshly grated Parmesan cheese
- salt and fresh ground black pepper to taste
Instructions
- Peel onions, cut in to slices about 1/2 inch (1.25 cm) thick, and separate into rings.
- Put onion rings into a large Ziploc bag.
- In a small bowl, stir together balsamic vinegar, Spike Seasoning, and dried thyme. Whisk in olive oil.
- Pour marinade into plastic bag and let onions marinate in the refrigerator 4 hours or longer, turning a few times if you’re home.
- Preheat oven to 400 F/200 C.
- While oven preheats, drain onions in a colander placed in the sink.
- Spray non-stick baking sheet with olive oil or non-stick spray.
- Arrange onions on baking sheet, putting them in a single layer as much as you can.
- Roast onions 30 minutes (or slightly longer), turning about every 10 minutes.
- Onions are done when they are nicely browned, especially on the edges.
- Remove onions to serving dish, sprinkle with Parmesan cheese, season to taste with salt and fresh ground black pepper and serve hot.
Notes
Use any type of sweet onion for this recipe. If you don't have Spike Seasoning (affiliate link) use any all purpose seasoning mix.
Nutritional information is calculated based on the fact that most of the marinade is drained away and not eaten.
Recipe created by Kalyn.
Nutrition Information
Yield
6Serving Size
1Amount Per Serving Calories 119Total Fat 5.2gSaturated Fat .9gTrans Fat 0gUnsaturated Fat 3.9gCholesterol 1.2mgSodium 208mgCarbohydrates 17gFiber 2.1gSugar 11gProtein 2.3g
Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.
Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Roasted Vidalia Onions are a bit of a carb splurge for low-carb diets (and too high in carbs for Keto) but I would eat a small serving of this for a treat. Although onions are approved for every phase of the South Beach Diet, sweet onions like this are higher in sugar, and would probably be phase 2 or 3 for South Beach.
Find More Recipes Like This One:
Use Side Dishes to find more side dish recipes like this one! Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.
Historical Notes for this Recipe:
The Roasted Vidalia Onions were first posted in 2009 when I bought a big bag of onions as part of a fundraiser. The recipe was last updated with more information in 2025.
31 Comments on “Roasted Vidalia Onions”
If you click the link in the recipe it will tell you what it is. You can substitute other types of all-purpose seasoning.
What is Spike Seasoning please
wow these sound awesome! I love the sweetness of Vidalia onions 🙂
All I can say is Yummmmm. I've really started to enjoy onions in my kitchen. This looks sooo good.
Kalyn,
Ok, so now I've gotta go buy some vidalias.
I remember seeing this recipe and thinking it sounded wonderful. I love all things onion – I'm home from work on my lunch break and will slice and put in marinade before heading back to the office. Thanks Kalyn!
This looks so crazy good. I have a serious onion addiction, so this is right up my alley.
Trying it this weekend.
Those onion rings look fabulous, Kalyn! I bet it would work with regular cooking onions too. And red onions!! Wouldn’t that be fantastic?
-Elizabeth
Thanks, Kalyn, I like so much caramelized onions and yours look terrific!
I am enjoying so much hosting WHB, and learn so many new vegs and cooking!
Roasted onions are amazing! I bet these with the extra flavor from the marinade are out-of-this-world.
I was going to caramelize some Vidalia onions to go on grilled hamburgers tonight – think I’ll try this instead! Thanks.
This looks so good; I am craving good Vidalias. I am originally from south Georgia, and my family would bake them or microwave them with some butter and salt and pepper. This recipe makes me want some soooo badly!
Vidalias are my favorites. I love to grill them in the summertime and toss them into salads and pastas. You’re making me so hungry right now.
Awesome, Kalyn!
Walla Walla onions are delicious!
and you can visit me if I can visit you:)
Kalyn, I could eat the caramelized onions alone but since you’ve added cheese…double my portion!
Fantastic use of these tasty onions. Marinated and then roasted. Just yum!
OMG! this onions looks delicious!!!!
Kalyn,
Great idea!
Oh duh, you can tell I was writing this last night after a stressful night of picking paint and carpet colors for my new addition! Sorry about leaving out the amount for olive oil. It’s 1/4 cup olive oil, will add that right now.
Just in time! I also bought a 10lb bag of these onions from a school fundraiser. I will be trying this recipe out next week!
How much olive oil did you use? You didn’t put it in the ingredients. This looks awesome! I can’t wait to try it!
This sounds like a great recipe. I’ll be trying this one soon!
I adore caramelized onions, I could put them on all of my sandwiches (except maybe pbj’s) and happy. Thanks for this!
TW, I think I learned about marinating onions from another blogger but can’t remember who it was. They’re great!
Katie, I have stuffed Vidalias on my list of things to try. Sounds fantastic!
Lisa, haven’t heard about Texas 1015 onions, will have to look for those. Marinating the onions before roasting makes them so tasty!
I have four pounds of Texas 1015 onions, also sweet, and have been looking for ways to eat them. I love that you marinated the onion before caramelizing them–I never thought of that before!
These look really great! I often do a similar thing with vidalias (or other sweet onions when I can’t find vidalias), but I’ve never added parmesan, and that sounds like a great addition.
I grew up in North Florida and thought that vidalias were the standard type of onion for a while because they were so easy to find and were served at every restaurant. Boy was I sad to learn that this isn’t the case everywhere! I eat a ton of them when I can find them, though, and just made stuffed vidalias last night 🙂
Makes my mouth water just thinking about it. It never occured to me that you could marinate onions.
Cookin’ Canuck, and Grace, I agree, Walla Walla onions would be a great choice for this too. I see those in the stores here sometimes.
Murasaki, I love roasted or fried onions in just about anything!
I love this already and I haven’t even tasted it yet. Caramelized onions…is there anything better?
(Well yes there is but they’re pretty damn good. 😉
Wow, these look REALLY good. Too bad dinner is over already. We don’t have Vidalia onions here in Oregon, but I bet this would also taste great with Walla Walla onions.
Awesome, Kalyn! I really enjoy the flavor of caramelized sweet onions. Walla Walla onions are also at the top of my list, along with Vidalias.