Sweet Vidalia Onion Roast

Featured in: Vegetarian Favorites

This dish features large Vidalia onions roasted whole until tender and soft, enhanced by fresh thyme, garlic, and butter. The onions, left unpeeled and scored at the top, slowly cook wrapped in foil in a hot oven. During roasting, the herbs and butter infuse the onions with rich flavor and aroma. Basting with melted butter and sprinkling fresh parsley before serving elevates the dish’s simple elegance. Perfect as a side or vegetarian option, it pairs wonderfully with grilled vegetables or roast meats. The natural sweetness of Vidalia onions shines through this effortless preparation.

Updated on Tue, 18 Nov 2025 13:13:00 GMT
Steaming-hot, golden brown Onion Boil with meltingly soft centers and herb-infused butter. Pin
Steaming-hot, golden brown Onion Boil with meltingly soft centers and herb-infused butter. | forkandbloom.com

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

I first made Onion Boil for a family dinner when I wanted something cozy and easy yet special enough for guests. The aroma while roasting is absolutely irresistible.

Ingredients

  • Vidalia onions: 4 large, unpeeled (or sweet onions)
  • Unsalted butter: 4 tbsp
  • Fresh thyme: 4 sprigs
  • Garlic: 4 cloves, peeled
  • Kosher salt: 1 tsp
  • Black pepper: ½ tsp, freshly ground
  • Fresh parsley: 2 tbsp, chopped (optional garnish)

Instructions

Preheat Oven:
Preheat your oven to 400°F (200°C).
Prep Onions:
Trim just 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 a square of heavy-duty foil. Sprinkle with salt and pepper.
Add Herbs & Butter:
Press 1 tbsp butter, 1 sprig thyme, and 1 garlic clove into the cut top of each onion.
Wrap:
Wrap each onion tightly in foil and set on a baking sheet.
Roast:
Roast for 1 hour 10 minutes, until the onions are very tender when pierced with a knife.
Serve:
Carefully unwrap, remove skins, and transfer to serving plates. Spoon over any melted butter from the foil. Sprinkle with parsley, if desired.
Fragrant foil-wrapped Onion Boil, glistening from the oven, ready to serve as a side dish. Pin
Fragrant foil-wrapped Onion Boil, glistening from the oven, ready to serve as a side dish. | forkandbloom.com

My kids love helping me unwrap the warm, steaming onions, and it always feels like opening a flavorful present for dinner.

Serving Suggestions

Serve this elegant roasted onion alongside roast chicken, grilled steak, or as a vegetarian centerpiece with crusty bread and salad.

Variations

For extra flavor, add a splash of balsamic vinegar or a pinch of smoked paprika before roasting. Try different sweet onion varieties if Vidalia is unavailable.

Allergen & Nutrition Info

Contains dairy. Substitute vegan butter or olive oil for a dairy-free option. Each serving: 130 calories, 7 g fat, 19 g carbohydrates, 2 g protein.

Close-up of a perfectly roasted Onion Boil, showcasing the tender inside, ideal for serving. Pin
Close-up of a perfectly roasted Onion Boil, showcasing the tender inside, ideal for serving. | forkandbloom.com

For a truly memorable meal, let everyone open their baked onion at the table—the aroma is part of the magic.

Recipe Q&A

What type of onions work best for this dish?

Sweet large onions like Vidalia, Walla Walla, or Maui are ideal because of their mild, natural sweetness and tender texture when roasted.

Why are the onions roasted unpeeled?

Roasting with the skins intact helps the onions retain moisture and steam gently, resulting in tender, meltingly soft layers inside.

Can I add other seasonings besides thyme and garlic?

Yes, adding a splash of balsamic vinegar or a pinch of smoked paprika can enhance the flavor without overpowering the onion’s natural sweetness.

How do I know when the onions are done roasting?

The onions are ready when a knife pierces effortlessly and the layers are soft and tender all the way through.

What are some serving suggestions for this dish?

Serve alongside roast meats, grilled vegetables, or simply with crusty bread for a satisfying vegetarian option.

Is it possible to make this dish dairy-free?

Yes, substitute butter with vegan butter or olive oil to keep the dish dairy-free without losing richness.

Sweet Vidalia Onion Roast

Whole Vidalia onions roasted with aromatic herbs and butter until tender and flavorful.

Prep duration
10 min
Cooking duration
70 min
Complete duration
80 min


Skill level Easy

Origin American

Yield 4 Portions

Dietary specifications Vegetarian, Gluten-free

Components

Main

01 4 large Vidalia onions, unpeeled

Seasoning and Aromatics

01 4 tablespoons unsalted butter
02 4 sprigs fresh thyme
03 4 garlic cloves, peeled
04 1 teaspoon kosher salt
05 ½ 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 rest flat, keeping skins intact; make a shallow X-cut on the top of each.

Step 03

Season and Wrap: Place each onion on heavy-duty foil squares. Season with salt and pepper, then press 1 tablespoon butter, 1 thyme sprig, and 1 garlic clove into each cut top. Wrap tightly in foil.

Step 04

Roast Onions: Arrange wrapped onions on a baking sheet and roast for 1 hour and 10 minutes until very tender when pierced.

Step 05

Unwrap and Serve: Carefully unwrap onions, remove skins, transfer to plates, spoon over melted butter from foil, and garnish with parsley if desired.

Necessary tools

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

Allergy details

Review each ingredient for potential allergens and consult healthcare professionals if you're uncertain about anything.
  • Contains dairy (butter). Use vegan butter or olive oil for dairy-free option. Check labels for hidden allergens.

Nutritional information (per portion)

These values are provided as estimates only and shouldn't replace professional medical guidance.
  • Calories: 130
  • Fat: 7 g
  • Carbs: 19 g
  • Protein: 2 g