Roasted Vidalia Onions with Parmesan

Roasted Vidalia Onions with Parmesan are a delicious side dish idea for people who like sweet onions, and this is super easy to make! And sweet onions are relatively high in carbs, but if you use portion control 

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There’s nothing I love more than an ultra-easy recipe that produces a truly memorable dish, and this recipe for Roasted Vidalia Onions with Parmesan is definitely one of those. I recently bought a big bag of Vidalia onions as part of a fundraiser, so I’ve been thinking of ways to use them.

I used a few onions for the Greek Salad with Marinated Onions and Oregano, 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 roasting some marinated 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, but this recipe will be great with any type of sweet onion.

How to Make Roasted Vidalia Onions with Parmesan:

(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.)

1. Vidalia onions are white with a slightly golden skin, and usually they’re sold when they’re just medium-sized.
2. 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.
3. Whisk together balsamic vinegar, olive oil, Spike Seasoning, and dried thyme, and marinate onions for 4 hours or longer.
4. Let marinated onions drain well while you preheat the oven to 400 F.
5. When oven is hot, arrange onions on a baking dish.
6. 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.)
7. Serve hot, with a sprinkling of grated Parmesan.

More Recipes with Sweet Onions:

• Asian Cucumber Salad
• Middle Eastern Tomato Salad 
• Easy Grilled Vegetables

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Yield: Makes 6 side dish servings

Roasted Vidalia Onions with Parmesan

Prep Time 20 minutes

Cook Time 30 minutes

Additional Time 4 hours

Total Time 4 hours 50 minutes

Roasted Vidalia Onions with Parmesan 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

1. Peel onions, cut in to slices about 1/2 inch (1.25 cm) thick, and separate into rings.
2. Put onion rings into a large Ziploc bag.
3. In a small bowl, stir together balsamic vinegar, Spike Seasoning, and dried thyme. Whisk in olive oil.
4. Pour marinade into plastic bag and let onions marinate in the refrigerator 4 hours or longer, turning a few times if you’re home.
5. Preheat oven to 400 F/200 C.
6. While oven preheats, drain onions in a colander placed in the sink.
7. Spray non-stick baking sheet with olive oil or non-stick spray.
8. Arrange onions on baking sheet, putting them in a single layer as much as you can.
9. Roast onions 30 minutes (or slightly longer), turning about every 10 minutes.
10. Onions are done when they are nicely browned, especially on the edges.
11. 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:

6

Serving Size:

1
Amount 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.

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Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Although onions are approved for every phase of the South Beach Diet, sweet onions like I used for these Roasted Vidalia Onions with Parmesan are higher in sugar, and would probably be phase 2 or 3 for South Beach. For other low-carb diets you could eat a very small amount of this, but use portion control if you’re watching your carbs. See nutritional information to see if you want to indulge!

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:
These Roasted Vidalia Onions were first posted in 2009. The recipe was last updated with more information in 2023.

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