Buttery Whole Roasted Onions
Roasted onions are soft, sweet and perfect for serving alongside other roasted vegetables or meats (like this simple roasted chicken). Simply arrange trimmed whole onions in a baking dish, add butter and herbs, and then roast. Jump to the Whole Roasted Onions Recipe or watch our quick recipe video showing how we make them.
Watch us make the recipe
We’ve shared a few recipes starring onions before. We’ve shown you how to pickle them, turn them into dips and used them to make this three ingredient tomato soup. These whole roasted onions are just as good and can be used in so many ways.
Enjoy these roasted onions in the following ways:
- Alongside other side dishes like mashed potatoes, mushroom stuffing and roasted squash.
- Alone, spread onto some toast with a bit of extra salt and some better-quality balsamic vinegar or sherry vinegar.
- Dipped into sauce like Romesco sauce or this dreamy tahini sauce.
- Blended into soups like this creamy vegetable soup or this butternut squash soup.
How to roast whole onions
You can roast onions with the skins on and without any additional seasonings. That said, we add a few simple steps for making these onions extra flavorful.
Trim both ends on the onions, but leave the skins on. Trimming the top allows butter or oil and any herbs to fall down into the middle of the onions. Trimming the bottom, helps the onions stay put in the baking dish.
Season generously with salt and add a variety of herbs to the party. In our photos we have used bay leaves, rosemary, thyme and sage. These are classic and taste amazing with the roasted onions, but you can always substitute other herbs or use spice blends instead.
Broil the onions first. This is actually a trick we picked up after experimenting with making our own homemade pho. By broiling the onions in their skins, the tops char and add a nice toasty flavor to the dish. We also love the color you achieve.
Roast for a while and keep the onions covered. By covering the onions while they roast, they steam a bit inside the dish. This way, the onions stay succulent and turn extra soft.
For more roasted vegetable recipes, take a look at these:
Buttery Whole Roasted Onions
Roasted onions are soft, sweet and perfect for serving alongside other roasted vegetables or meats. You can roast onions with the skins on and without any additional seasonings. That said, we add a few simple steps for making these onions extra flavorful. For serving, we love adding a drizzle of balsamic or sherry vinegar over the onions. For the best flavor, use a better-quality vinegar.
You Will Need
6 small to medium onions, skins left on with top and bottom trimmed
3 tablespoons (42 grams) butter, cut into 6 slabs
1/2 teaspoon fine sea salt
1/2 teaspoon cracked black pepper
1 to 2 tablespoons chopped fresh herbs like thyme, rosemary or sage
3 bay leaves
Good quality balsamic vinegar, balsamic glaze or sherry vinegar, optional, to taste
Finishing salt like Maldon flaked salt, optional, for serving
Season both the top and bottom cut ends of each onion with the salt. Arrange onions in an oven-safe baking dish. Slide the onions underneath the broiler and broil until the tops are golden brown and some of the onion skin is charred.
Turn the oven to bake and heat to 400 degrees Fahrenheit.
Remove the baking dish from the oven and place a slab of butter on top of each onion and then mound the herbs onto the butter so that when it melts, they will fall down into and over each onion. Season with pepper and scatter the bay leaves around the onions.
Cover the baking dish with foil or tuck baking parchment paper into the corners so that the dish is well covered. Bake the onions until very soft and sweet, 60 to 90 minutes. Serve as is or with a drizzle of vinegar and a pinch of finishing salt over the top.
Adam and Joanne's Tips
- For a vegan version, substitute the butter for olive oil. Use about 2 tablespoons.
- Nutrition facts: The nutrition facts provided below are estimates. We have used the USDA database to calculate approximate values.