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Sweet Vidalia Onion Roast

Featured in: Everyday Dinners

This dish features whole Vidalia onions roasted slowly with fresh thyme, garlic, and butter, resulting in tender, aromatic layers bursting with natural sweetness. The onions are wrapped in foil to retain moisture and infused flavors as they cook for over an hour. After roasting, the skins are removed and the melted butter is spooned atop for richness. Garnished with fresh parsley, this preparation brings out the onion’s delicate texture and savory notes, perfect alongside grilled vegetables or roasted meats.

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Updated on Tue, 18 Nov 2025 14:26:00 GMT
Golden, caramelized Onion Boil with thyme and garlic, ready to be enjoyed as a side. Save to Pinterest
Golden, caramelized Onion Boil with thyme and garlic, ready to be enjoyed as a side. | bloomoven.com

A sweet, tender Vidalia onion roasted whole until meltingly soft, with aromatic herbs and butter: a simple yet elegant side dish.

The first time I made Onion Boil, I was impressed by how a humble onion could become the star of our dinner. Its sweet aroma filled our kitchen and brought everyone to the table eager to try a bite.

Ingredients

  • Vidalia onions: 4 large unpeeled onions (can use other sweet onions)
  • Unsalted butter: 4 tbsp for flavor and tenderness
  • Fresh thyme: 4 sprigs for herbaceous aroma
  • Garlic: 4 peeled cloves to add depth
  • Kosher salt: 1 tsp for seasoning
  • Freshly ground black pepper: ½ tsp for mild heat
  • Chopped fresh parsley: 2 tbsp optional garnish

Instructions

Prep Oven:
Preheat your oven to 400°F (200°C).
Trim Onions:
Trim the root ends and tops of each onion so they sit flat, leaving skins on.
Score Tops:
Use a paring knife to cut a shallow X into the top of each onion.
Season:
Place each onion on heavy-duty foil. Sprinkle with salt and pepper.
Stuff & Butter:
Press 1 tbsp butter, 1 sprig thyme, and 1 garlic clove into the cut top of each onion.
Wrap & Bake:
Wrap each onion tightly in foil and set on a baking sheet. Roast for 1 hour 10 minutes until very tender.
Finish & Serve:
Carefully unwrap, remove skins, and transfer to serving plates. Spoon over melted butter from foil. Sprinkle with parsley if desired.
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| bloomoven.com

This became a favorite side at family gatherings, where everyone marveled that onions could taste so luxurious. It always reminds me of simple moments together.

Required Tools

Baking sheet, heavy-duty aluminum foil, paring knife, oven

Nutritional Information

Calories: 130, Total Fat: 7 g, Carbohydrates: 19 g, Protein: 2 g (per serving)

Serving Suggestions

Serve alongside roast meats, grilled vegetables, or as a vegetarian main with crusty bread

A close-up of tender, slow-roasted Onion Boil glistening with melted butter on a plate. Save to Pinterest
A close-up of tender, slow-roasted Onion Boil glistening with melted butter on a plate. | bloomoven.com

Enjoy Onion Boil as a comforting addition to your favorite meals. You'll be amazed by its rich flavor and soft texture.

Recipe FAQs

→ What type of onions work best for this dish?

Sweet onions such as Vidalia, Walla Walla, or Maui provide the ideal natural sweetness and tenderness when roasted whole.

→ Why are the onions wrapped in foil during cooking?

Wrapping in foil traps steam and juices, helping the onions cook evenly and remain moist and tender.

→ Can I add other herbs or spices to enhance the flavor?

Yes, additions like smoked paprika or a splash of balsamic vinegar can complement the butter and thyme for extra depth.

→ How do I know when the onions are done?

The onions are ready when a knife pierces them easily and the layers feel meltingly soft to the touch.

→ Is this preparation suitable for vegetarian or gluten-free diets?

Yes, it uses simple, natural ingredients and is both vegetarian and gluten-free friendly.

Sweet Vidalia Onion Roast

Slow-roasted Vidalia onions with herbs and butter, soft and flavorful side dish option.

Prep Duration
10 min
Cook Duration
70 min
Entire Time
80 min
Created by Rachel Moore

Recipe Group Everyday Dinners

Skill Level Easy

Cuisine Type American

Makes 4 Portions

Dietary Info Vegetarian-Friendly, No Gluten

Ingredient List

Main

01 4 large Vidalia onions, unpeeled

Seasoning & Aromatics

01 4 tablespoons unsalted butter
02 4 sprigs fresh thyme
03 4 cloves garlic, peeled
04 1 teaspoon kosher salt
05 0.5 teaspoon freshly ground black pepper

Optional Garnish

01 2 tablespoons chopped fresh parsley

Directions

Step 01

Preheat oven: Preheat the oven to 400°F.

Step 02

Prepare onions: Trim the root ends and tops of each onion so they sit flat, keeping the skins intact.

Step 03

Score onions: Use a paring knife to cut a shallow X on the top of each onion.

Step 04

Season onions: Place each onion on a square of heavy-duty foil, sprinkle with kosher salt and black pepper.

Step 05

Add butter, thyme, and garlic: Press 1 tablespoon unsalted butter, 1 sprig thyme, and 1 garlic clove into the cut top of each onion.

Step 06

Wrap onions: Wrap each onion tightly in foil and arrange on a baking sheet.

Step 07

Roast onions: Roast for 1 hour and 10 minutes until the onions are meltingly tender when pierced with a knife.

Step 08

Serve: Carefully unwrap the foil, remove the skins, transfer onions to plates, spoon over any melted butter from foil, and sprinkle with chopped parsley if desired.

Essential Tools

  • Baking sheet
  • Heavy-duty aluminum foil
  • Paring knife
  • Oven

Allergy Notes

Review ingredients to spot any allergens and ask your healthcare provider if you're unsure.
  • Contains dairy from butter; use vegan butter or olive oil as a substitute for dairy-free diets.

Nutrition Details (per portion)

Use this info as a reference only; it doesn’t replace health guidance.
  • Caloric Value: 130
  • Fats: 7 g
  • Carbohydrates: 19 g
  • Proteins: 2 g