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Roasted Caramelized Onions

By America's Test Kitchen

Published on October 19, 2021

Yield

Makes about 2 cups

Roasted Caramelized Onions

Ingredients

3 tablespoons unsalted butter 4 pounds onions, halved and sliced ¼ inch thickSalt and pepper

Before You Begin

Be sure to use yellow onions here; sweet onions, such as Vidalia or Walla Walla, will make this recipe overly sweet and somewhat gummy. Serve these onions alongside a wedge of cheese as an appetizer, as a side dish for steak, or as a sandwich topping.

Instructions

  1.  Adjust oven rack to lower-middle position and heat oven to 400 degrees. Coat inside of Dutch oven with vegetable oil spray.
  2.  Melt butter in prepared pot over medium-low heat. Stir in onions and 1 teaspoon salt. Cover, place pot in oven, and roast for 1 hour (onions will be moist and slightly reduced in volume).
  3.  Working quickly, remove pot from oven and stir onions, scraping bottom and sides of pot. Partially cover, return pot to oven, and continue to roast until onions are deep golden brown, 1½ to 1¾ hours, stirring onions and scraping bottom and sides of pot every 30 minutes.
  4.  Remove pot from oven, stir to scrape up any browned bits, and season onions with salt and pepper. Serve warm or at room temperature. (Onions can be refrigerated for up to 1 week.)
Roasted Caramelized Onions
Photography by Steve Klise.

Roasted Caramelized Onions

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By America's Test Kitchen
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Yield

Makes about 2 cups

Ingredients

3 tablespoons unsalted butter
4 pounds onions, halved and sliced ¼ inch thick
Salt and pepper

Ingredients

3 tablespoons unsalted butter
4 pounds onions, halved and sliced ¼ inch thick
Salt and pepper

Ingredients

3 tablespoons unsalted butter
4 pounds onions, halved and sliced ¼ inch thick
Salt and pepper

Why This Recipe Works

Caramelizing onions on the stovetop requires patience and a watchful eye. Enter roasting. Our approach is essentially hands-off, allowing the onions to turn golden, soft, and sweet in the oven where the steady, even heat promises even cooking. After slicing up 4 pounds of onions and stirring them into melted butter in a Dutch oven, much of our work was done. The onions roasted in the covered pot, cooking down and shedding their moisture in a 400-degree oven. An hour in, we gave the pot a decisive stir, loosening any bits stuck to the sides and bottom. Leaving the lid ajar for the last hour and a half encouraged all excess moisture to evaporate, giving us deeper browning and sweet, concentrated flavor. Our finished onions boasted profound, nuanced sweetness, and scraping up and stirring the fond into the golden strands made them all the richer.

Before You Begin

Be sure to use yellow onions here; sweet onions, such as Vidalia or Walla Walla, will make this recipe overly sweet and somewhat gummy. Serve these onions alongside a wedge of cheese as an appetizer, as a side dish for steak, or as a sandwich topping.

Instructions

  1.  Adjust oven rack to lower-middle position and heat oven to 400 degrees. Coat inside of Dutch oven with vegetable oil spray.
  2.  Melt butter in prepared pot over medium-low heat. Stir in onions and 1 teaspoon salt. Cover, place pot in oven, and roast for 1 hour (onions will be moist and slightly reduced in volume).
  3.  Working quickly, remove pot from oven and stir onions, scraping bottom and sides of pot. Partially cover, return pot to oven, and continue to roast until onions are deep golden brown, 1½ to 1¾ hours, stirring onions and scraping bottom and sides of pot every 30 minutes.
  4.  Remove pot from oven, stir to scrape up any browned bits, and season onions with salt and pepper. Serve warm or at room temperature. (Onions can be refrigerated for up to 1 week.)

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