Sweet onions sautéed until tender are wonderful on their own but stir in those flavors found in French onion soup, layer with creamy ricotta and Gruyère then bake in a flaky, buttery pastry crust and you might have a slice of savory heaven!
French onion soup is a classic and a favorite in our family – its deep earthy notes are welcome any day of the year. Transporting those delectable notes to a tart is easy and the results are amazing.
Onions are a versatile summer vegetable and luckily available year round. I always cook with sweet onions. They lend the essence of the onion without the bitterness that often comes from white onions. There are a wide variety of sweet onions including two of the best, the Sweet Texas 1015 and Vidalia, both in peak season spring through summer.
The depth of flavor in these tarts begins with the sautéed onions and comes courtesy of a splash of white wine plus a smidge of brown sugar and molasses – ingredients found in a wonderful French onion soup – followed with a touch of fresh thyme.
Then underneath those luscious onions is a blend of ricotta and Gruyère providing a bed of creaminess.
Finally everything is wrapped in a tender pastry crust and baked until golden with a final sprinkling of Gruyère.
Making the tarts is a multi-step process, all quite simple. You can sauté the onions and whip up the cheese filling ahead of time and refrigerate until you’re ready to bake or the tarts can be made a day ahead and reheated. And don’t be intimated by making the pastry crust – this is one of the easiest yet most divine crusts you can make. It’s a quick mix in your food processor then a simple roll of the dough, fill and fold.
Serve these rustic tarts as a light lunch, as side or quartered for an appetizer. Elegant or casual and perfect for any occasion!
French Onion Rustic Tart
For the onions:
2 tablespoons butter
2 tablespoons olive oil
2 large sweet onions, sliced thin, about 4 cups
¼ cup good white wine, such as Sauvignon Blanc
1 teaspoon brown sugar
1 teaspoon molasses
2 teaspoons fresh thyme leaves
½ teaspoon kosher salt
¼ teaspoon freshly cracked black pepper
Melt the butter with the olive oil in a large skillet over medium heat. Add the onions and cook until they are tender and translucent, about 30 minutes.
Add the white wine and cook until the wine is completely absorbed into the onions, about 3 to 4 minutes. Toss in the thyme, brown sugar, kosher salt and pepper along with the molasses.
Stir to mix into the onions. Set aside to cool completely.
For the filling:
1-½ cups ricotta cheese
1-¼ cup shredded Gruyère cheese, divided
¼ teaspoon kosher salt
¼ teaspoon freshly cracked black pepper
In a small bowl combine the ricotta cheese with 1 cup of the Gruyère plus the kosher salt and black pepper.
Stir to blend together.
For the pastry:
1-½ cups all-purpose flour, plus extra for rolling out the dough
⅛ teaspoon kosher salt
1 tablespoon sugar
¾ cup unsalted butter, 1-½ sticks
⅓ cup cold water
1 egg
1 tablespoon water
Cut the butter into cubes and chill in the freezer for about 30 minutes.
Combine the flour, kosher salt and sugar in a food processor, mix for about 5 to 10 seconds. Scatter the cold butter cubes on top of the flour.
Pulse about 10 times, just until the butter is the size of peas.
Add the cold water and process for about 10 to 15 seconds, or just until the water is blended into the flour and butter. The pastry dough will be crumbly in appearance. Don’t over process or your pastry will be tough.
Turn out the mixture on a lightly floured surface and lightly dust your hands with flour. Gently gather the dough together and divide into 4 equal pieces, about 4-¼ ounces each. Roll each section of the dough into a round about ⅛” thick. Turn the dough occasionally as you roll it so the dough doesn’t stick to the surface, adding a light dusting of flour as needed.
Transfer each round to large, rimmed baking sheets, lined with parchment paper, with 2 rounds per sheet so that you have room to work.
Divide the ricotta filling between each round of dough, placing it in the center and spreading slightly, leaving about 2” around the edges.
Top with the sautéed onions.
Pull the dough up over the edge of the ricotta filling and onions in small sections, folding as you go.
Whisk the egg and 1 tablespoon of water together. Using a pastry brush, lightly brush the egg wash over the pastry dough.
Bake in a 375-degree oven for 40 minutes or until the crust is golden. Sprinkle the remaining ¼ cup of Gruyère cheese over the top of the tarts. Bake for an additional 5 minutes.
Serve warm or at room temperature. Refrigerate leftovers tarts. Reheat in a 350-degree oven for about 10 to 12 minutes.
Makes 4 tarts, about 5″ each.
French Onion Rustic Tart
Equipment
- Large skillet
- Food processor
- 2 Large rimmed baking sheets
Ingredients
- For the onions:
- 2 tablespoons butter
- 2 tablespoons olive oil
- 2 large sweet onions, sliced thin – about 4 cups
- ¼ cup good white wine, such as Sauvignon Blanc
- 1 teaspoon brown sugar
- 1 teaspoon molasses
- 2 teaspoons fresh thyme leaves
- ½ teaspoon kosher salt
- ¼ teaspoon freshly cracked black pepper
- For the filling:
- 1-½ cups 1-½ cups ricotta cheese
- 1-¼ cups shredded Gruyère cheese, divided
- ¼ teaspoon kosher salt
- ¼ teaspoon freshly cracked black pepper
- For the crust:
- 1-½ cups all-purpose flour, plus extra for rolling out the dough
- ⅛ teaspoon kosher salt
- 1 tablespoon sugar
- ¾ cup unsalted butter, 1-½ sticks
- ⅓ cup cold water
- 1 extra-large egg
- 1 tablespoon water
Instructions
- Preheat the oven to 375-degrees.
- For the onions:
- Melt the butter with the olive oil in a large skillet over medium heat. Add the onions and cook until they are tender and translucent, about 30 minutes.
- Add the white wine and cook until the wine is completely absorbed into the onions, about 3 to 4 minutes.
- Toss in the thyme, brown sugar, kosher salt and pepper along with the molasses. Stir to mix into the onions. Set aside to cool completely.
- For the filling:
- In a small bowl add the ricotta cheese with 1 cup of the Gruyère plus the kosher salt and black pepper. Stir to blend together.
- For the pastry crust:
- Cut the butter into cubes and chill in the freezer for about 30 minutes. Combine the flour, kosher salt, and sugar in a food processor, mix for about 5 to 10 seconds.
- Scatter the cold butter cubes on top of the flour and pulse about 10 times, just until the butter is the size of peas.
- Add the cold water and process for about 10 to 15 seconds, or just until the water is blended into the flour and butter. Don’t over process or your pastry will be tough. The pastry dough will be crumbly in appearance.
- Turn out the mixture on a lightly floured surface and lightly dust your hands with flour. Gently gather the dough together and divide into 4 equal pieces, about 4-¼ ounces each. Roll out the dough into a round about ⅛” thick. Turn the dough occasionally as you roll it so the dough doesn’t stick to the surface, adding a light dusting of flour as needed.
- To assemble the tarts:
- Transfer each round to large, rimmed baking sheets, lined with parchment paper, with 2 rounds of dough per sheet so that you have room to work.
- Divide the ricotta filling between each round of dough, placing it in the center and spreading slightly, leaving about 2” around the edges.
- Top with the sautéed onions, dividing between each tart.
- Pull the dough up over the edge of the ricotta filling and onions in small sections, folding as you go.
- Whisk together the egg and 1 tablespoon water. Using a pastry brush, lightly brush the egg wash over the pastry dough
- Bake in a 375-degree oven for 40 minutes or until the crust is golden. Sprinkle the remaining Gruyère cheese over the top of the tarts. Bake for an additional 5 minutes.
