How to Bake an Onion in the Oven

by Molly Thompson

Onions are more than just garnish for hamburgers or steak.

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Onion slices on hamburgers, minced onions on hot dogs or chili, and chopped onions in spaghetti sauce or meatloaf -- these are the ways that many people use onions, in or on something else. Surprisingly, baked sweet onions are a tasty, healthy side dish on their own. Bake them whole, sliced or cut open like a flower blossom to make a simple side dish for meat or poultry dishes, or serve them with a dipping sauce as a tasty appetizer.

Peel the onions and cut off the tops. Discard the peel and the tops.

Place the onions in a shallow baking dish with 1/2 to 1 cup of water in the bottom. Bake the onions, uncovered, at 300 degrees Fahrenheit for 1 to 1 1/2 hours, until the onions are soft when you squeeze them.

Dot the onions with a little butter or margarine and sprinkle them with the salt and pepper. Bake them for 10 to 15 more minutes.

Remove the onions from the oven and transfer them to a serving dish. Sprinkle with balsamic vinegar or grated Parmesan cheese, if desired.


  • For an attractive appetizer variation, peel the onion and remove the top. Slice wedges down into the onion without cutting all the way through so it falls open like a flower. Bake as directed in the steps and remove from the oven. Sprinkle with margarine, salt, pepper and Parmesan cheese. Serve with a spicy ranch dipping sauce.

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About the Author

As a national security analyst for the U.S. government, Molly Thompson wrote extensively for classified USG publications. Thompson established and runs a strategic analysis company, is a professional genealogist and participates in numerous community organizations.Thompson holds degrees from Wellesley and Georgetown in psychology, political science and international relations.