Introduction

This viral TikTok Onion Boil recipe transforms a simple sweet onion into a tender, flavorful dish with layers of rich seasoning and caramelized goodness. It’s an easy, impressive side that pairs beautifully with a variety of meals.

A single cooked onion sits on a white plate with a white marbled surface beneath, its layers soft and translucent, forming a smooth, round mound about three layers thick. The onion is coated evenly with a glistening layer of orange-red oil infused with visible granules of spices, including black and red pepper flakes, spreading around its base like a small, vibrant pool. The texture of the onion is tender, with some slight caramelization visible on top where a few layers curl inward, showing a darker, rich spice-coated center. The light reflects softly on the oily surface, highlighting the contrast between the pale onion and the fiery colored oil and spices. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 large (15 ounce) sweet onion, peeled and ends trimmed off
1 tablespoon vegan butter
1 tablespoon extra virgin olive oil
1 teaspoon cajun seasoning
¼ teaspoon salt (plus more to taste when serving each layer)
Optional additional seasonings: ¼ teaspoon garlic powder, ¼ teaspoon old bay seasoning
Optional garnish: finely diced parsley leaves

Instructions

Step 1: Preheat your oven to 375 degrees F.
Step 2: Use a small melon baller to scoop out the top center portion of the onion about one-third of the way down, creating a well in the middle.
Step 3: Place the onion on a sheet of aluminum foil and add the vegan butter into the well.
Step 4: Mix the cajun seasoning, olive oil, and any optional seasonings together, then pour the mixture over the butter inside the well, allowing it to drip down the sides of the onion.
Step 5: Sprinkle the onion with ¼ teaspoon salt and any additional salt to taste.
Step 6: Wrap the onion tightly in the aluminum foil, ensuring it is fully sealed, and place it in a small baking dish or cast iron skillet to catch any drippings.
Step 7: Roast the wrapped onion on the center rack of the oven for 1 hour.
Step 8: Remove the onion from the oven, carefully open the foil, and check for tenderness—the onion should be fork-tender, the center should jiggle, and the exterior slightly caramelized. If needed, reseal the foil and bake for an additional 10 minutes, then recheck.
Step 9 (optional): For a deeper caramelization, turn the oven to broil. Open the foil, drizzle extra melted butter or olive oil, and sprinkle a little more salt over the onion. Broil for 5-10 minutes, watching closely to avoid burning.
Step 10: To serve, peel away the outer layer and enjoy each tender layer beneath with an extra sprinkle of salt if you like. Pour all the juices from the foil over the onion to maximize flavor. This dish pairs wonderfully with rice, crispy chickpeas, or roasted vegetables such as Brussels sprouts.

Tips & Variations

Use a sweet onion like Vidalia or Walla Walla for the best natural sweetness and tenderness.
Experiment with seasonings such as smoked paprika or chili flakes for different flavor profiles.
Adding fresh herbs like thyme inside the well before roasting can add subtle aroma and complexity.
For a non-vegan option, substitute vegan butter with regular butter for a richer taste.

Storage

Store any leftover cooked onion in an airtight container in the refrigerator for up to 3 days. Reheat gently in a microwave or covered skillet until warmed through. Avoid overheating to keep the layers tender and juicy.

How to Serve

A close-up view of a single round dish in a white bowl, featuring a soft, cooked white onion at the center, covered with translucent, glistening onion layers seasoned with dark red and black spices. The onion sits in a shallow pool of bright orange oil mixed with tiny dark specks of herbs and spices. A silver fork is partially inserted into the onion from the left side, lifting a few glossy onion layers. The bowl is set on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use regular onions instead of sweet onions?

Yes, but sweet onions are preferred because they become tender and caramelize nicely. Regular onions may taste more pungent and less sweet after roasting.

Do I need to wrap the onion in foil?

Wrapping the onion in foil traps the steam and juices, helping it cook evenly and stay tender. It’s an important step for achieving the soft, caramelized texture.