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5 from 3 votes

Roasted Red Onions Recipe

Roasted Red Onions are an unexpected and amazing vegetarian side dish -- or an ingredient that can be added to dozens and dozens of recipes. The slow roasted whole onions transform from raw, firm and sharp, to sweet, soft, and aromatic.
*Please note that the active work time is only about 15 minutes.
Prep Time15 minutes
Cook Time3 hours 30 minutes
Total Time3 hours 45 minutes
Course: Side Dish
Cuisine: American
Keyword: vegetarian comfort foods, roasted onions
Servings: 10 as a side
Calories: 150kcal

Ingredients

  • 10 small red onions (about 5 to 6-ounces each)
  • 5 tablespoons extra virgin olive oil
  • a few sprigs of fresh rosemary, thyme and oregano washed & dried
  • 2 tablespoons unsalted butter
  • salt and pepper

Instructions

  • Set oven. Preheat the oven to 300°F, and adjust a rack to the center.

Prep Onions

  • Leaving the skin on, wash and dry the onions. Then, with the skin still on, root end off of each one, just about ½ — only enough to create a base so the onions don’t roll. Then, slice about 1-inch off the tip (top) end of each one, and use the knife to mark an “X” the surface, only cutting into it about ½-inch or so. Place them in a 9 x 13 x 2-inch pan, on their bases.
  • Drizzle about 3 tablespoons of the olive oil on the flat surface of the onions -- over the "X." Sprinkle generously with salt and pepper.

Roast the Onions

  • Place in the preheated 300°F oven, uncovered.
    After 1 hour, remove them from the oven and drizzle with the remaining 2 tablespoons of oil. Then cover the pan lightly with foil, return them to the oven for 1 more hour.
  • Remove the onions from the oven again and take off the foil. Add about half of the fresh herb sprigs to the pan, surrounding, and on top of the onions. Evenly distribute the butter among the onions, on the top center of each one.
    Uncovered, return the onions to oven and roast for another 30 minutes.
    Baste the onions with the juices from the bottom of the pan and turn the heat up to 350°F.
    Continue to roast for 1 to 2 more hours, basting them every 20 minutes with more juices from the bottom of the pan. (It's your call -- the longer you roast, the more caramelized and soft they'll be.)
    And for an even deeper flavor, when you turn the oven up to 350°F, peel and cut the onions into quarters from the "X" at the top.
  • Cool and serve. Remove from the oven and let them cool in the pan. Once they’re cool enough to touch, take off the skins, slice and serve with the remaining fresh herbs. (If you haven't already cut them, I slice them into quarters from the "X" at the top.)

Notes

Calorie count is only an estimate.

Nutrition

Calories: 150kcal