Caramelized Onion Tart

Updated on February 17, 2017
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Exploring food facts, folklore, and fabulous recipes... one ingredient at a time.

James Beard was an American chef, food writer, and an eccentric personality who brought French cooking to Middle America. His legacy lives on in twenty books, numerous writings, his own foundation, and his annual Beard awards in various culinary genres.

And he loved onions.

James Beard's devotion to the allium family is easy to understand: the onion is versatile and appears in almost every cuisine. It grows in many different soil types and climate zones, stores well, and can be transported long distances without spoiling. Most researchers agree that the onion has been cultivated for 5,000 years or more and that they were first grown in Iran and West Pakistan.

This onion tart recipe showcases their flavor and texture.

I crawled into the vegetable bin, settled on a giant onion and ate it, skin and all. It must have marked me for life for I have never ceased to love the hearty flavor of onions.

— James Beard
4 stars from 1 rating of Onion Tart

Equipment You Will Need

  • Mandoline or food processor with slicing blade (not mandatory, but will make preparation of this dish much easier (and less tearful)
  • Sharp knife
  • Cutting board
  • Baking sheet
  • Paper towels
  • Large sauté pan
  • Measuring cups and spoons

Cook Time

Prep time: 40 min
Cook time: 25 min
Ready in: 1 hour 5 min
Yields: 6 servings


  • 1 tablespoon olive oil
  • 1 tablespoon unsalted butter
  • 1 pound yellow onions, thinly sliced
  • 1 pound red onions, thinly sliced
  • 1/2 pound cipollini, vertically sliced in 1/4 inch slices
  • 2 tablespoons fresh thyme, minced
  • 1/2 tsp. freshly ground black pepper
  • 1/2 tsp. salt
  • 1/2 of a 14-oz. pkg. refrigerated pie dough
  • 1/4 cup Feta cheese, crumbled
  • 1/4 cup Parmesan cheese, shredded
  • 1/4 cup Gorgonzola cheese, crumbled
  • 1 large egg, beaten


  1. Preheat oven to 425 degrees F.
  2. Peel the onions. Using a mandoline or the slicing blade of a food processor, thinly slice the yellow and red onions. Slice the cipollini with a sharp knife. Line a baking sheet with paper towels; place the onions on the paper towels, and allow to sit for about 10 minutes to remove some of the excess moisture. (Did you know that onions are 89 percent water?)
  3. Heat the oil and butter in a large sauté pan over medium heat. Place the onions, thyme, salt, and pepper in the pan and cook, stirring occasionally about 20 minutes or until the onions are softened and begin to turn golden brown. Don't hurry the process by turning up the heat--the onions will burn and taste bitter. You want them to caramelize.
  4. Line a 10-inch tart pan with the pie dough.
  5. Sprinkle feta cheese on the pastry, followed by the parmesan and gorgonzola cheeses. Top with the onion mixture. Bake at 425° for 25 minutes or until golden. Cool for 10 minutes.

What Makes This Recipe Work?

Perhaps you are wondering why there are three different types of onions listed in this recipe. Gertrude Stein wrote "a rose is a rose is a rose," but not all onions are created equal.

Yellow onions turn a rich, dark brown when caramelized and give French onion soup its sweet flavor. Red onions hold their shape and have a more assertive "onion-y" taste. Cipollinis are tender and very sweet.

Questions & Answers

    © 2013 Linda Lum


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      • Carb Diva profile image

        Linda Lum 4 years ago from Washington State, USA

        Thanks Vacation Trip. My daughters are vegetarian and so I am always looking for new and creative ways to prepare non-meat meals. I hope you like it.

      • Vacation Trip profile image

        Susan 4 years ago from India

        Wow. Onion Tart i have never heard of this. This looks yummy and sounds good. Thank you for sharing. Voted up.