What is an onion boil?

An onion boil is actually a roasted whole onion that's been seasoned and wrapped in foil, then baked until incredibly tender. Despite the name "boil," this cooking method uses dry heat from the oven rather than boiling water, creating concentrated flavors and a wonderfully caramelized result.

Is an onion boil good for you?

Absolutely! Onions are packed with nutrients, including vitamin C , fiber, and powerful antioxidants called flavonoids. When prepared this way with minimal added fats, you're getting all the nutritional benefits of onions in a delicious, satisfying form that encourages you to eat more vegetables.

How much time to boil onions?

This roasted onion boil takes about 1 hour in a 375°F oven, though cooking time can vary slightly depending on the size of your onion. You'll know it's ready when the entire onion is fork-tender and the center jiggles slightly when gently shaken.

Is it okay to boil onions?

Yes, cooking onions thoroughly is not only okay but recommended! Cooking onions actually breaks down their cell walls, making their nutrients more bioavailable and creating the sweet, mellow flavor we love. The high heat also eliminates the sharp bite of raw onions while developing complex, caramelized flavors.

Delicious Onion Boil Recipe

Description

This easy, foil-wrapped recipe delivers a tender, caramelized onion packed with Cajun flavors perfect for any meal. So buttery and flavorful, it disappears from the table faster than you’d expect!

Ingredients

Scale

1 large (15 ounce) sweet onion, peeled and ends trimmed off
1 tablespoon vegan butter
1 tablespoon extra virgin olive oil
1 teaspoon cajun seasoning
1/4 teaspoon salt (plus more to taste when serving each layer)
Optional: 1/4 teaspoon garlic powder, 1/4 teaspoon old bay seasoning
Optional garnish: finely diced parsley leaves

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Instructions

Preheat oven to 375°F and position the rack in the center.
Use a melon baller to scoop out a well in the onion’s center. Place the onion on foil and add butter to the well. Mix cajun seasoning with olive oil, pour into the well, and season with salt and optional spices.
Wrap tightly in foil and place in a baking dish or skillet.
Roast for 1 hour. Check doneness: the onion should be fork-tender with slight caramelization. Cook 10 more minutes if needed.
(Optional) Broil for 5–10 minutes with extra butter or oil and salt for a golden top.
Serve immediately, peeling the outer layer and drizzling juices over the onion. Add salt if desired.

Notes

Use large sweet onions (e.g., Vidalia) for best results.
Create a pocket when scooping the center, don’t hollow out completely.
Seal foil tightly to trap steam, but leave room for circulation.

Prep Time: 5 minutes
Cook Time: 1 hour
Category: Side Dish
Method: Oven Roasted
Cuisine: American

Nutrition

Serving Size: 1/2 onion
Calories: 125
Sugar: 8g
Fat: 9g
Carbohydrates: 12g
Fiber: 3g
Protein: 2g