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Marinated Roasted Onions

Perfect with steak or chicken… or anything, really!

I don’t know that there’s any other ingredient that adds as much flavor to a wide variety of dishes as the humble onion. And that’s precisely why they also make the perfect side – they go with just about everything and they elevate the dishes you pair them with to new heights. And these Marinated Roasted Onions, well, with them it’s more like soaring new heights since they’re impossibly soft and imbued with a sweet and tangy herb-kissed flavor.

These are simple to make but they are SO delicious. As far as the marinating goes, longer is better – while I like to let them sit overnight for the best flavor, an hour will do if that’s all you’ve got. So what’s in that marinade? Excellent question. It’s just red wine vinegar, honey, rosemary, and a bit of water. (I told you it was simple.)

That sweet and tangy combination softens the harsh bite of the onions and all you have to do is cut them in half and place them in the mixture to get a nice long soak. A pat of butter goes on top of each onion before they head into the oven, where they hang out for about an hour so they have plenty of time to soften into melt-in-your-mouth goodness.

Serves 6

5m prep time

1h cook time

8h inactive

Rated 4.8 out of 5
Rated by 8 reviewers
  • 1 cup water
  • 1 cup red wine vinegar
  • 1 tablespoon honey
  • A few springs fresh rosemary, chopped
  • 4 medium to large yellow onions
  • 4 tablespoons butter
  • Kosher salt and freshly cracked black pepper, to taste
  1. Trim ends from onions, but do not peel. Slice in half horizontally and leave the skins intact to protect the onion during cooking.
  2. In a small bowl, whisk together water, red wine vinegar, honey, and about a teaspoon of chopped rosemary.
  3. Pour mixture into a baking dish that will hold all of the onions, about 2 quarts in size.
  4. Arrange onions cut side down in marinade and cover dish with plastic wrap. Ideally, chill overnight, but at least 1 hour.
  5. Preheat oven to 400°F.
  6. Turn onions over so larger cut-side faces up. Place a pat of butter on top of each onion and sprinkle with a bit of chopped rosemary. Season with salt and pepper.
  7. Bake, uncovered, for 1 hour, basting onions with marinade once or twice during the cooking time.
  8. Remove outer skins before serving. Enjoy!

Recipe adapted from Kevin is Cooking.

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