Sweet Vidalia Onion Roast

Featured in: Everyday Joyful Meals

This dish features large Vidalia onions roasted whole with salted butter, fresh thyme, and garlic cloves to develop a tender, melting texture. Wrapped tightly in foil and cooked slowly, the onions absorb the aromatic flavors while softening to a delicate finish. Perfectly seasoned and optionally garnished with fresh parsley, this straightforward method highlights the natural sweetness and softness of the onions, making an elegant, easy side for various meals.

Updated on Tue, 18 Nov 2025 13:09:00 GMT
Golden-brown Onion Boil with fragrant thyme and melted butter, perfect for a cozy dinner. Pin It
Golden-brown Onion Boil with fragrant thyme and melted butter, perfect for a cozy dinner. | platefullyjoy.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 holiday gathering, and everyone kept asking for seconds. The buttery aroma while roasting was irresistible, and it proved to be a comforting addition to our meal.

Ingredients

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

Instructions

Preheat Oven:
Preheat your oven to 400°F (200°C).
Prep Onions:
Trim just the root ends and tops so each onion sits flat, leaving their 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 Aromatics:
Press 1 tbsp butter, 1 sprig thyme, and 1 garlic clove into the cut top of each onion.
Wrap and Roast:
Wrap each onion tightly in foil and set on a baking sheet. Roast for 1 hour 10 minutes, until very tender.
Serve:
Carefully unwrap, remove skins, and transfer to plates. Spoon melted butter from foil over onions. Sprinkle with parsley if desired.
Steamy close-up of a tender Onion Boil, revealing the sweet onion's soft, caramelized layers. Pin It
Steamy close-up of a tender Onion Boil, revealing the sweet onion's soft, caramelized layers. | platefullyjoy.com

This dish became a family favorite for Sunday dinners: my little one loves peeling the sweet onion layers, and we swap stories while enjoying every buttery bite.

Serving Suggestions

Try with roast meats, grilled vegetables, or as a hearty vegetarian main with crusty bread and a salad.

Flavor Variations

Add a splash of balsamic vinegar or a pinch of smoked paprika before wrapping for extra depth and complexity in the finished dish.

Kitchen Tools Needed

You only need a baking sheet, heavy-duty foil, paring knife, and oven: simple tools for delicious results.

Whole roasted Onion Boil, seasoned with garlic, ready to be served as a delightful side. Pin It
Whole roasted Onion Boil, seasoned with garlic, ready to be served as a delightful side. | platefullyjoy.com

Onion Boil is the kind of comforting side that brings everyone together. Once you taste its gentle sweetness, you'll return to this recipe often!

Recipe FAQs

What type of onions work best for this preparation?

Sweet onions like Vidalia, Walla Walla, or Maui are ideal since their natural sugars caramelize during roasting, enhancing flavor and texture.

Why wrap the onions in foil before roasting?

Foil traps steam and moisture, helping the onions cook evenly and become meltingly tender while infusing the butter and herbs.

Can I add other seasonings to enhance flavor?

Yes, try additions like balsamic vinegar or smoked paprika for a subtle tang or smoky depth to complement the onions.

How do I tell when the onions are done roasting?

The onions are ready when a knife pierces easily and the layers feel soft and fully cooked inside.

Are there suitable butter substitutes for dairy-free versions?

Vegan butter or olive oil can replace unsalted butter to maintain richness while accommodating dietary preferences.

Sweet Vidalia Onion Roast

Whole Vidalia onions roasted with buttery herbs for a tender, flavorful side.

Time to Prep
10 minutes
Time to Cook
70 minutes
Overall Time
80 minutes
Recipe by Olivia Reed


Skill Level Easy

Cuisine American

Makes 4 Number of Servings

Diet Info Vegetarian-Friendly, No Gluten

What You'll Need

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

Step-by-Step Guide

Step 01

Preheat Oven: Set the oven to 400°F and prepare for roasting.

Step 02

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

Step 03

Score Onions: Use a paring knife to make a shallow X cut across the top of each onion.

Step 04

Season and Fill: Place each onion on a piece of heavy-duty foil. Sprinkle with salt and pepper, then press 1 tablespoon butter, 1 thyme sprig, and 1 garlic clove into the cut top.

Step 05

Wrap and Roast: Wrap each onion tightly in foil and set on a baking sheet. Roast in the oven for 1 hour and 10 minutes until tender.

Step 06

Unwrap and Serve: Carefully remove foil and discard skins. Transfer onions to plates, spoon over any melted butter from the foil, and garnish with chopped parsley if desired.

Tools You'll Need

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

Allergy Notice

Be sure to review ingredients for allergens. When unsure, talk with a healthcare provider.
  • Contains dairy from butter; substitute with vegan butter or olive oil for dairy-free preparation.

Nutrition (For Each Serving)

Nutritional details are meant for general guidance. Don't rely on them for medical reasons.
  • Calorie Count: 130
  • Fats: 7 g
  • Carbohydrates: 19 g
  • Proteins: 2 g