Caramelized Onions (in the Oven)
Try our Caramelized Onions – they are made in the oven, which is the easiest method to prepare them. This easy recipe is hands-free, delicious tasting, and makes a versatile addition to any of your favorite dishes.

Tell Us About These Caramelized Onions
We love caramelized onions, but instead of standing by the stovetop for about an hour to caramelize them, try this easy method! Simply slice the onions and bake them on a cookie sheet with three ingredients for about 30 to 40 minutes. They will turn out perfectly every time. Best of all – the oven does all the work, it’s hands-free!
Caramelized onions are a simple dish to serve as a side or have them readily available to top your favorite barbecue dishes, grilled flank steak, hot dogs, burgers, chicken cutlets, and more.
This recipe was given to me by my cousin, Guilianna, while we were in Sicily. In the old days, this dish was a typical peasant dish and was served as a side dish to enjoy with some crusty bread. Today, we love them especially to top almost anything, like grilled chicken, burgers, meats, bratwurst sandwiches, and even on top of pizza.
What are Caramelized Onions?
Caramelized onions are onions that have been slowly cooked down and usually over low heat until they become golden brown, and the sugars break down to become sweet and intense in flavor. But this is a NEW method for making caramelized onions, and it’s easier and simpler, the Italian way!
Recipe Tips
- This is a recipe that doesn’t have exact measurements of ingredients. We used only 4 ingredients, and you’ll see why with our descriptions below.
- Keep in mind, onions will most likely make you cry while slicing them. So we suggest you run them under water for a few seconds before slicing. This will help a little, but not totally.
- Also, when slicing, they do not have to be perfect.
- Plus, we used two large onions, but you can use smaller ones and add as many slices as you can fit onto your baking sheet.
- When baking the onions in the oven, there’s no need to turn them over; they will caramelize on the bottom.
- When serving, you will need to use a spatula to pick up and “flip each one” (sliced rings of onion) onto your serving platter for better presentation.
- These caramelized onions can be served warm, cold, or at room temperature.
What You’ll Need to Make these Caramelized Onions
For our recipe, you will need the following four ingredients: 2 large onions, extra virgin olive oil, salt, and sugar. Oh, and you can garnish with any fresh herbs you may have on hand.

How to Make Caramelized Onions in the Oven?
If this is your first time making these caramelized onions, no worries, it’s very easy. First, gather your 4 ingredients. Plus, our full printable recipe is located at the bottom.
- First, prepare your baking sheet. Drizzle some extra virgin olive oil, and use your hand to spread it over your baking sheet. Then lightly scatter some sugar over the entire surface.

2. Take your onion, peel, and remove its skin. Then place it onto a cutting board, and slice it into 1/4 to 1/2-inches thick (as shown in the photos below). QUICK NOTE: They do not have to be perfect. Plus, you can use a mandolin slicer, if that helps.

3. Place the onion slices onto your prepared baking sheet, side by side. Lightly scatter with salt on top and then drizzle lightly with some olive oil.

4. Bake in the oven at 375ยฐF (180C) for about 30 to 40 minutes until the onions are golden brown around the edges. Remove, use a spatula to flip them over onto a serving platter, garnish with any sprigs of fresh herbs, and serve.

FAQ’s
- Can we make ahead? Yes, you can certainly make them ahead, then reheat them in the oven, and to your preference.
- How to store them? Place them into a container, and keep them chilled in your refrigerator. They will stay fresh for up to two days.
- Can we freeze them? We don’t recommend it. We have never done it before.

A Wonderful Side or Condiment…
Caramelized Onions in the oven is an ideal method to use to make your favorite condiment or side.
We served them the other night with our parmesan crusted chicken cutlets, and everyone took these caramelized onions and placed them on top of their chicken cutlets and LOVED them even more. Try them…
and ENJOY!
If you try our caramelized onions in the oven recipe, let us know and leave a comment with a star rating! Have fun and snap a photo, and hashtag it on Instagram @2sistersrecipes, and Pinterest. We’d love to see what you cook!
More Delicious Ideas
- Authentic Tzatziki Sauce
- Homemade Refrigerator Pickles Recipe
- Shrimp Avocado Salsa Dip
- Fresh Orange Avocado Salsa

Caramelized Onions in the Oven
Try our Caramelized Onions - they are baked in the oven, which is the easiest method to prepare them. This easy recipe is hands-free, delicious tasting, and makes a versatile addition to any of your favorite dishes.
Ingredients
- extra virgin olive oil
- 2 large onions ( or more as needed)
- some granulated sugar
- salt
- fresh sprigs of thyme, as garnish
Instructions
1. Preheat your oven to bake at 375°F (180C).
2. First, prepare your baking sheet. Drizzle some extra virgin olive oil, and use your hand to spread it over your baking sheet. Then lightly scatter some sugar over the entire surface.
3. Take your onion, peel and remove its skin. Then place it onto a cutting board, and slice it into 1/4 to 1/2-inches thick (as shown in the photos below). QUICK NOTE: They do not have to be perfect. Plus, you can use a mandolin slicer, if that helps.
4. Place the onion slices onto your prepared baking sheet, side by side. Lightly scatter with salt on top and then drizzle lightly with some olive oil.
5. Bake in the oven at 375°F (180C) for about 30 to 40 minutes until the onions are golden brown around the edges. Remove, use a spatula to flip them over onto a serving platter, garnish with any sprigs of fresh herbs, and serve.
Notes
- This recipe calls for 2 large onions. But you can use smaller sizes and as many onions as you need to fit on your baking sheet.
- Keep in mind, all ovens vary. So the time to bake will vary as well. Best to keep an eye on them after 30 minutes.
- The onions will have a golden brown coloring on the bottom. Therefore, it's best to FLIP them over when transferring to a serving platter.
Nutrition Information:
Yield: 6 servings Serving Size: 1 servingAmount Per Serving: Calories: 41Total Fat: 2.4gCarbohydrates: 5.2gFiber: .7gSugar: 3.5gProtein: .4g
Happy and Healthy “4th of JULY” Everyone!
Thanks for stopping by…
xo anna and liz
FREE EMAIL BONUS
Weeknight Dinners Made Easy
Tips & recipes for delicious meals . . . no matter your skill level!
FREE EMAIL BONUS
Weeknight Dinners Made Easy
Tips & recipes for delicious meals . . . no matter your skill level!