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Five Onion Tart with Arugula Salad

  • Serves: 8
  • Prep Time: 1 hr 5 min
  • Cook Time: 1 hr 35 min
  • Calories: 394
Tart made with chives, red onions, leeks, topped with Arugula Salad

Like a quiche but with fewer eggs, a golden, buttery crust, and a medley of onions cooked to caramelized perfection this onion tart is ideal for brunch, but makes a delicious dinner, too.

Onion Tart, S'il Vous Plait!

The whole idea of an onion tart is so very French—take a few ingredients, cook them just-so and then bring them together so carefully, so thoughtfully that voila, an elegant meal is born from almost nothing. Perhaps the most famous onion tart was served at New York City’s iconic Lutèce, prepared by its (maybe equally iconic) chef André Soltner as an homage to a favorite meal from his childhood in Alsace. So the story goes, his mother would take him along with her when she had errands to run, and when they were finished, they’d stop at a café where they’d have a glass of wine (for her) and a slice of tart l’onion (for him). We’ve taken the inherently humble tart—if something with a cream-laced custard and a butter crust can be truly called “humble”— and leaned even harder into its onion-ness by using not one but five kinds of onion in the tart. We serve it with a simply dressed arugula salad, which is—in our opinion—the ideal complement to this rich tart.

onions, shallots, chives, leeks, green onions, flour, butter, creme fraiche, arugula and eggs on a counter

A Caramelized Onion Tart Recipe, All Dressed Up for Spring

Honestly, you could make this tart any time of the year, because it’s so easy to find these onions in grocery stores. But alliums like chives and scallions are early harbingers of warmer weather, and in the spring and early summer especially, we crave their verdant color and bright, sharp flavors. In this onion tart, we combine the onion-y power of these five wonderful alliums:

  • Scallions

  • Shallots

  • Yellow onion

  • Leeks

  • Chives

flour, butter, shortening, and salt in a food processor
flour, butter, shortening, and salt blended together in a food processor
flour, butter, shortening, and salt blended together in a food processor with ice water
tart crust pressed into a tart pan

How To Make The Best Caramelized Onion Tart

Every good tart begins with a terrific crust, and this stunner is no exception. We use a combination of butter and shortening to make for a supremely flakey, rich crust that you’ll blind bake so that it stays lovely and crisp—no soggy bottoms here! From there, the success of your tart is largely dependent on your patience. You must have the patience to caramelize the onions before adding them to the custard mixture. It’s not hard to do, but it does take a little time. Here’s our step-by-step guide to making the very best French onion tart.

  1. Caramelize the onions. Cook the onions, leeks, scallions and shallots on low heat, covered for 10 minutes, uncovered for about 30, until they’re caramelized. Let them cool.

  2. Make the custard base. Whisk together the eggs, crème fraîche, salt, nutmeg, pepper, chives and caramelized onions.

  3. Assemble the onion tart! Pour the custard mixture into the blind-baked crust.

  4. Bake! It’ll take about 25 minutes—just until the eggs are set.

  5. Bonus! This onion tart can be made up to a day ahead. Store it in the fridge overnight and when it’s time to warm it up, cover it and bake at 300°F until it’s warmed through.

shallots, leeks, green onions and yellow onions being cooked in a pan with butter
beaten eggs in a bowl with minced chives, salt and pepper
shallots, leeks, green onions and yellow onions caramelized in a pan with butter stored by a wooden spoon
egg and caramelized onion mixture for onion tart

Tools You’ll Need

raw onion tart ready to be baked
freshly baked onion tart
onion tart with a slice removed with and arugula salad

Elegant, Springy Egg Recipes for Brunch, Lunch or Dinner

onion tart with and arugula salad
onion tart with a slice removed with and arugula salad

Sophisticated, Easy, and Always a Favorite

If you whip up this magically both easy and impressive onion tart recipe, we’d love to hear about it! Share a photo and tag us on Instagram using @themodernproper and #themodernproper so that we can see your stuff! Happy eating!

Five Onion Tart with Arugula Salad

  • Serves: 8
  • Prep Time: 1 hr 5 min
  • Cook Time: 1 hr 35 min
  • Calories: 394

Ingredients

Tart Crust

  • 1/2 cup Unsalted butter, chilled and cut into small pieces
  • 1/2 cup Vegetable shortening
  • 2 cups All purpose flour, plus more for rolling out dough
  • 1/2 tsp Sea salt
  • 5-6 tbsp Ice water

Tart & Salad

  • 4 Tbsp Butter
  • 2 Tbsp Olive oil, plus more for salad
  • 1 Large yellow onion, thinly sliced
  • 2 Leeks, sliced
  • 4 Green onions, thinly sliced
  • 2 Shallots, thinly sliced
  • 4 Eggs
  • 1/3 cup Crème fraîche
  • 1/2 tsp Salt, plus more to taste
  • 1/4 tsp Nutmeg
  • 1/2 tsp Freshly ground pepper, plus more to taste
  • 1/2 cup Chives, minced
  • 4 cups Arugula

Method

  1. Pulse the butter, shortening flour and salt together in the base of a food processor (alternatively you can cut the butter and shortening into the flour by hand with a fork or pastry cutter) until butter and shortening are pea sized. Add the ice water one tablespoon at a time pulsing or mixing until dough just starts to come together. Do not over mix. Using your hands form a ball with the dough, wrap it in saran wrap and chill in the refrigerator for 30 minutes.
  2. On a lightly floured surface roll out dough into a circle ¼-inch thick. Carefully press the dough into a tart pan, cutting away excess dough. Puncture dough with a fork a dozen times and chill for 30 minutes longer.
  3. Preheat oven to 400°F. Cover the pie with a piece of foil and bake for 20 minutes. Remove the foil and continue to bake for another 10 minutes, or until crust is just set.
  4. In a large saucepan with a tight fitting lid set over medium heat, melt 4 tablespoons butter and 2 tablespoons oil. Reduce heat to medium-low and add onions, leeks, scallions and shallots. Cover with a lid and cook for 10 minutes. Remove cover and continue to cook, stirring often, until onions turn a golden brown color. This process should take about 30 minutes. Remove from heat and allow to cool, about 20 minutes.
  5. In a large bowl whisk together eggs, crème fraîche, salt, nutmeg, pepper and chives. Add the onion mixture to the egg mixture and stir until onions are evenly distributed. Pour into the tart crust and bake for 25-35 minutes, until eggs are set and the crust is golden brown.
  6. Just before serving toss the arugula with desired amount of olive oil, salt and pepper. Add the salad to the top of the tart and serve.

    **Tart can be made up to a day ahead. To warm up, cover and bake at 300°F until warmed through.