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Onion Boil Recipe
Ash Tyrrell

Onion Boil Recipe

I’ll be honest — the first time I made this Onion Boil, I thought it sounded too simple to be exciting. But once I opened the foil and saw the buttery, seasoned onions steaming away, I knew I’d discovered something special. Each layer turned tender, slightly sweet, and full of savory flavor.
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Total Time 1 hour 25 minutes
Ingredients Method Notes

Ingredients
  

  • 1/2 cup 1 stick unsalted butter – Good-quality butter gives the dish its rich flavor and silky finish.
  • 4 teaspoons paprika – Adds mild smokiness and a beautiful warm color.
  • 1 tablespoon garlic powder – Provides savory depth without overpowering the onion.
  • 2 teaspoons kosher salt – Enhances sweetness and balances all flavors.
  • 2 teaspoons Old Bay seasoning – Gives the dish a classic boil-style seasoning blend.
  • 1 teaspoon dried thyme – Adds earthy warmth that complements roasted onion.
  • 1 teaspoon freshly ground black pepper – Fresh pepper delivers better aroma and bite.
  • 4 large yellow onions preferably sweet onions – Sweet varieties soften beautifully and caramelize nicely during roasting.
  • Fresh parsley finely chopped (optional garnish) – Adds color and freshness before serving.

Method
 

  1. Start by heating your oven to 375°F so it’s fully ready for roasting. Cut large foil squares so each onion can be completely wrapped. Proper wrapping ensures steam stays trapped inside.
  2. Combine softened butter with paprika, garlic powder, salt, Old Bay seasoning, thyme, and black pepper in a bowl. Mix until smooth and evenly blended. This seasoned butter becomes the flavor base for the entire dish.
  3. Trim both ends of each onion so they sit flat on the baking sheet. Peel off the outer skin and carefully cut out a small core from the center without slicing through the bottom. Scoring the top helps seasoning soak in.
  4. Place seasoned butter into the hollowed center and spread a little on top of each onion. Set onions onto foil squares and wrap tightly so juices don’t escape. Proper sealing ensures tender results.
  5. Place wrapped onions on a baking sheet and bake for about 55–65 minutes. The onions should feel soft when pierced with a fork. Slow roasting allows flavors to fully develop.
  6. Carefully open foil packets after allowing onions to cool briefly. Spoon melted butter over the onion before serving and garnish with parsley if desired. The aroma alone is irresistible.

Notes

  • I always choose sweet onions because they become extra tender and flavorful.
  • Letting onions rest for a few minutes before opening foil keeps juices from spilling out.
  • Sometimes I uncover onions for the last few minutes to lightly caramelize the tops.
  • I like serving onions over rice or mashed potatoes to soak up extra butter sauce.
  • Adding a splash of lemon juice at the end brightens the flavor nicely.