This recipe was originally published on January 5, 2018.

Make ahead marinated red onions are simple to make, and look elegant when served on a fancy platter. The secret ingredient is time, so make sure to allow enough time for the them to marinate overnight.

This recipe is a huge hit with my three girls. Honestly, who doesn't love the smell of onions roasting in the oven on a cold winter day?

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Questions
How to Make
Variations
Pro Tips
Recipe

Questions

Are marinated red onions good for you?

Red onions are the highest in antioxidant compounds.
Fermented vegetables have probiotics, which helps maintain a healthy gut.
They have anti-inflamatory properties due to the flavonoid quercetin.
They are high in fiber, folic acid, and vitamin B.

How do you cut onions without tears?

Use a sharp knife. This will give you a cleaner cut so it will cause less damage to the cell wall which will produce less chemicals in the air.
Chill the onion in the fridge or briefly in the freezer before slicing. It will retard the release of the sulfuric compounds.
Run a vent hood and slice near it. It will take the fumes away from your eyes and bring them outside.

How many calories are in one serving?

For a serving size of half an onion, there is 86 calories and 13.3g carbs. This recipe is also low in fat and cholesterol. For more nutritional information, scroll past the recipe card.

How to Make

Find all your ingredients then measure out the two vinegars, spices, brown sugar, and butter.

Use a sharp knife to cut off both ends of each red onion then slice the onion in half. To help ease the tears, read my suggestions above. Keep the outer skin on, as it helps them keep their shape. Place them with the largest cut side down in a large baking pan with sides.

Make the marinade by placing all the ingredients in a bowl.

Whisk until well combined.

Pour the marinade over top.

If you want, sprinkle more fresh rosemary over the cut ends of the red onion. Cover with foil and refrigerate for at least 12 hours.

Cook uncovered at 400 F for 30 minutes. Flip each onion over and put a pat of butter on top. Sprinkle more fresh rosemary and a few grinds of black pepper on top. Put back in the oven and bake for 15 minutes more.

Take them out and baste them with the marinade using a large spoon. Put back in the oven for another 15 minutes of cooking, baste again, then repeat this process once more.

Before serving, remove the tough outer skin. Pour the warm marinade in a small bowl.

Serve hot on a fancy platter with hot the marinade on the side. Your guests then can spoon more delicious marinade over this side dish to intensify the flavor.

This tasty marinade comes together super fast, and the prep work is quick. Really, what's not to like? Experience something new, and give it a try this week.

Variations

Need to substitute an ingredient in the marinade? The basic ingredients are water, vinegar, sweetener, and spices.
Looking for a sugar substitute? Try honey, maple syrup, or rice malt syrup.
Don't have fresh rosemary? Switch out with another earthy spice like thyme or oregano.

Pro Tips

Make this the night before to give time for them to marinade for maximum flavor.
Keep the onion skins on while baking to help keep their shape. Just remove them before eating.
The marinade makes this vegetable more flavorful and easier to digest.
For best flavor, marinate and roast them with the flat side down in the marinade, and then turn them over half way through.
Tempted to skip the basting? This is an important part of increasing the flavor of the dish.
Don't throw the marinade out; keep it for guests to spoon over their side dish.

Enjoy onions with these delicious recipes.

The pleasure of a 5-star review would be greatly appreciated.

Recipe

Make Ahead Marinated Red Onions

5 from 1 reviews

Author: Brooke
Prep Time: 10 minutes
Cook Time: 1 hour 15 minutes
Total Time: 1 hour 25 minutes
Yield: 8 servings 1x

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Description

Make ahead marinated red onions is a healthy recipe that's also super easy. The red onions are marinated in balsamic vinegar, brown sugar, and other seasonings, then roasted in the oven. This popular dish is low carb, gluten free, and has many health benefits. Just start this simple side dish the night before your next potluck, family gathering, or holiday meal.

Ingredients

Scale

For the Marinade

1 cup water (236 ml)
½ cup sherry vinegar (118 ml)
½ cup white balsamic vinegar (118 ml)
2 tablespoons light brown sugar, packed
1 heaping teaspoon fresh rosemary, chopped
½ teaspoon salt
⅛ teaspoon black pepper

For the Roasted Onions

4 large red onions
2 tablespoons salted butter (28g)
1 teaspoon fresh rosemary, chopped
a few grinds of black pepper

Instructions

Cut the ends off the red onions, then halve them. Keep the skins on, as it helps them keep their shape. Place them flat side down in a baking pan with sides.
Whisk together the water, vinegars, brown sugar, and spices, and then pour over the onions. Cover with foil and allow to marinate for a minimum of 12 hours.
Cook uncovered at 400 F for 30 minutes. Flip each onion over, put a pat of butter on top of each onion, sprinkle the rosemary and a few grinds of black pepper on top.
Cook for 15 minutes more, then take out the pan and baste them with the marinade. Repeat this step two more times.
Remove the tough outer skins, then serve warm on a pretty platter. Pour any leftover marinade from the baking pan into a small bowl and serve with this dish.

Notes

Make this the night before to give time for them to marinade for maximum flavor - 12 hours is best for maximum flavor.
The onion skins should be kept on while baking to help keep their shape. Remove before eating.
Start by marinating and roasting them with the flat side down in the marinade then turn them over half way through for the best flavor.
Don't skip the basting part. This important part increases the flavor of the dish.
Keep the marinade for guests to spoon over their serving.

Category: Dinner
Method: Baked
Cuisine: American

Keywords: soak, vinegar