Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Check Icon Print Icon Note Icon Heart Icon Filled Heart Icon Single Arrow Icon Double Arrow Icon Hamburger Icon TV Icon Close Icon Sorted Hamburger/Search Icon

Alsatian Onion Tart

Scott Phillips

Servings: four for supper, eight as a starter.

This classic French regional tart of good Gruyère and “melted” onions, bound with a savory custard, is one of my favorites. For an interesting variation, brush the prebaked tart shell with a thin layer of Dijon mustard, or add 1 Tbs. of finely minced tarragon to the custard. Be sure to buy the best quality Gruyère.


  • 2 Tbs. vegetable oil
  • 2 Tbs. unsalted butter
  • 4 medium onions, cut in half and very thinly sliced
  • A sprinkling of granulated sugar
  • Kosher salt and freshly ground black pepper
  • 3 large eggs
  • 1-1/4 cups heavy cream
  • A tiny pinch nutmeg (preferably freshly grated)
  • 1/3 cup (about 1-1/4 oz.) finely grated Gruyère
  • 1 partially baked tart shell in a 10-inch porcelain quiche pan or a 10-1/2- or 11-inch metal tart pan 

Nutritional Information

  • Calories (kcal) : 450
  • Fat Calories (kcal): 330
  • Fat (g): 37
  • Saturated Fat (g): 20
  • Polyunsaturated Fat (g): 3
  • Monounsaturated Fat (g): 11
  • Cholesterol (mg): 180
  • Sodium (mg): 450
  • Carbohydrates (g): 23
  • Fiber (g): 1
  • Protein (g): 8


  • Heat the oil and butter in a cast-iron or other heavy-based 10-  to 12-inch skillet. Add the onions and sugar, season with salt and pepper, and sauté over medium-high heat, stirring frequently, until lightly browned. Lower the heat and continue to cook the onions until very soft and evenly browned, stirring frequently, another 30 to 40 minutes; you may need to add a little more oil. When the onions are done, transfer them to a strainer and drain.
  • Heat the oven to 375°F. If using a tart pan with a removable bottom, put it on a baking sheet. In a bowl, whisk the eggs and cream. Season with 3/4 tsp. salt, a scant 1/2 tsp. pepper, and the nutmeg. Add the drained onions and half of the cheese and blend thoroughly. Fill the prepared tart shell with the onions and custard. Top with the remaining cheese and bake until the tip of a knife comes out clean and the top of the tart is puffed and brown, 40 to 45 minutes. Let cool for at least 15 to 20 minutes before serving.


Rate or Review

Reviews (5 reviews)

  • HisCovenant | 10/16/2019

    This was so yummy! My onions only got caramelized and weren’t close to melting... next time I’ll try a lower temp and double cook time to prevent browning and change texture to melty... but the other ratios were spot on!

  • Pumpkiesmom | 09/11/2014

    Quick and easy. A keeper.

Show More

Rate this Recipe

Write a Review


View All


Follow Fine Cooking on your favorite social networks

We hope you’ve enjoyed your free articles. To keep reading, subscribe today.

Get the print magazine, 25 years of back issues online, over 7,000 recipes, and more.