# Onion Boil

A whole onion steamed in butter and bold Cajun seasoning until meltingly tender — a viral side that punches well above its ingredient count.

_Side · Southern American_

Prep: 5 min · Cook: 45 min · Total: 50 min · Yields: 2 servings

## Ingredients

- 2 large yellow onions (peeled, root end intact)
- 3 tbsp unsalted butter (divided, cut into pats)
- 2 tsp Cajun seasoning
- ½ tsp garlic powder
- ½ tsp smoked paprika
- ¼ tsp black pepper
- 1 pinch cayenne pepper (optional, for heat)
- ½ tsp kosher salt
- 2 tsp fresh parsley (chopped, for garnish)

## Instructions

1. Preheat the oven to 400 °F (205 °C).
2. Slice about 0.5 inch off the top of each of the 2 large yellow onions. Keep the root end intact so the onion holds together during cooking.
3. Set each onion cut-side up on a sheet of heavy-duty aluminum foil large enough to wrap it completely.
4. Using a small spoon or your fingers, gently separate the top layers of each onion to open a pocket for the seasoning.
5. Mix together the 2 tsp Cajun seasoning, 0.5 tsp garlic powder, 0.5 tsp smoked paprika, 0.25 tsp black pepper, and 0.5 tsp kosher salt in a small bowl.
6. Spoon the seasoning blend evenly into the opened layers of each onion, pressing it down so it settles between the rings.
7. Add a pinch of cayenne pepper into each onion if using, distributing it among the layers.
8. Divide the 3 tbsp unsalted butter into pats and tuck them into the layers of each onion, spreading the butter across both onions.
9. Wrap each onion tightly in its foil, crimping the edges to seal so steam cannot escape.
10. Place the foil-wrapped onions directly on the oven rack or on a baking sheet and roast for 40–45 minutes, until the onions are completely tender when pierced through the foil with a skewer.
11. Carefully open the foil away from you — the steam is very hot. The butter and seasoning will have formed a glossy, fragrant sauce pooled at the base.
12. Transfer each onion to a bowl or plate, spoon any sauce from the foil over the top, and garnish with the 2 tsp fresh parsley before serving.

## Tip

> Keep the root end fully intact — it acts as a natural base that holds all the layers together. If it's cut through, the onion falls apart and the butter sauce leaks out into the foil before it can soak in.

Tags: comfort-food, vegetarian, one-pan, weeknight, cajun

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Canonical: https://just-recipes.io/recipes/onion-boil