Adam was the first to suggest testing whole roasted onions, and I am so happy that he did! I was initially skeptical, but these sweet, soft, roasted onions have become one of my favorite holiday recipes. They are stunning on the table and taste incredible. I can’t wait for you to try this easy recipe. For more onion recipes, see our roasted onion dip and my absolute favorite French onion soup (really, it’s so good!).
Key Ingredients
Onions: I love using small to medium yellow or sweet onions for this recipe. When they are available, I love Walla Walla or Vidalia onions! Butter: I bake my onions with butter, making them so delicious. Salted butter is perfect, but unsalted is perfectly fine! Plant-based butter works in this recipe. Herbs: To make our roasted onions super flavorful, I add lots of chopped fresh herbs like thyme, rosemary, and sage. If you can find them, look for the poultry herb packet, which usually has all three inside. You can use dried herbs for these baked onions; I included tips in the recipe below. Vinegar: This is optional, but I love drizzling the onions with thick balsamic vinegar before serving.
How to Make Roasted Onions
You can roast onions with their skins on (like roasted garlic). However, I like to take a few extra steps to make this extra special. First, trim both ends of the onions, but leave the skins intact. Trimming the top allows our butter and herbs to seep down into the center of the onions while trimming the bottom helps them stay put in the baking dish. Next, season generously with salt and broil the onions briefly. This technique, borrowed from making homemade pho, chars the tops of the onions in their skins, adding a delightful toasty flavor and a beautiful caramelized color. Then I add a bit of butter and a variety of herbs. I love bay leaves, rosemary, thyme, and sage, which complement the roasted onions beautifully. Finally, I roast the onions covered, which allows them to steam a bit and makes them extra soft and sweet. These are lovely with roasted chicken and are a staple on our Thanksgiving table next to our herb roasted turkey. They are especially good with a drizzle of turkey gravy. Enjoy these roasted onions alongside mashed potatoes, mushroom stuffing, and roasted butternut squash. Or blend them into soups to make them sweet and creamy. I especially love these blended into our roasted cauliflower soup and this butternut squash soup. 3 tablespoons (42g) butter, cut into 6 thin 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 Finishing salt like Maldon flaked salt, optional 2Slide the onions underneath the broiler and broil until the tops are golden brown and some onion skin chars. 3Turn the oven to bake and heat to 400°F (204°C). 4Remove the baking dish from the oven and place a slab of butter on top of each onion. Then, mound the herbs onto the butter so that they will fall into and over each onion when the butter melts. 5Season with pepper and scatter the bay leaves around the onions. 6Cover the baking dish with foil or tuck baking parchment paper into the corners to cover the dish well. 7Bake 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.
