Similar to a Quiche, this Onion and Mushroom Tart in Puff Pastry delivers incredible onion flavor that is accented with savory sautéed mushrooms finished with a splash of Madeira. It’s perfect for a brunch or light dinner. Leftovers, if any, are just as good the next day reheated.
It has quickly become an absolute favorite of the Master Taste Tester – so much so that it’s not unusual that we have it at least once a week. I first blogged about this delicious tart on March 19, 2017. Since then, I’ve learned some things along the way, so decided that was time to update not only the photographs, but also some aspects of the actual recipe.
Ingredients for Onion and Mushroom Tart in Puff Pastry:
I used the following ingredients: Sheet of store-bought puff pastry, unsalted butter, onions, dried thyme, salt, freshly ground black pepper, mushrooms, Madeira, eggs, and half-and-half. In the past, I used store-bought pie crust, with mixed results. I’ve also used my Foolproof Pâte Brisée Tart Crust that produces an exceptional Onion and Mushroom Tart. However puff pastry is so much easier!
Forming the Puff Pastry for the Onion and Mushroom Tart.
After letting the puff pastry sheet thaw completely, I rolled it out on a floured surface to about an 11 or 12-inch square. Then, I transferred it to my 9-inch tart pan with a removable bottom. I cut away the excess puff pastry, leaving about 1/2-inch, that I tucked down around the sides of the tart pan.
Once the crust was formed, I put it into the freezer for about 30 minutes. Over the years, I’ve learned that freezing the crust before baking it is one of the keys to preventing it from shrinking during cooking. After 30 minutes, I pricked the bottom of the crust with a fork to prevent it from puffing up during cooking. I also lined the crust with a crumpled piece of parchment paper, and filled the parchment paper with dried beans. You could also use pie weights here. The reason that I crumple the parchment paper is that it fits much more easily into the crust. The other thing that I’ve learned in terms of preventing shrinkage of the pastry during baking is to fill the pan with weights.
I popped the puff pastry crust into a preheated 400° F oven for about 25 minutes until the sides started to brown. I removed it from the oven, and carefully removed the parchment paper with the beans. Then, I returned the crust to the oven for another 5 minutes to brown the sides and bottom that had been covered in the parchment paper.
Cooking the Onions:
Now was the time to make the filling. I started with the onions which I added to melted butter in a 12-inch skillet over medium heat. I added the thyme, salt, and pepper, gave the onions a stir, covered the pan, and cooked the onions over medium heat for about 15 minutes, stirring occasionally. Then, I uncovered the pan, and cooked the onions for another 10 minutes over medium heat. Depending on the onions, there may still be a fair amount of liquid in the pan after 25 minutes. If so, I used a paper towel to “mop up” the excess liquid. I removed the pan from the heat, and let the onions cool.
Cooking the Mushrooms:
Now for the mushrooms – I took the chopped mushrooms by the handful and squeezed as much liquid as I could from them. Then, I placed the squeezed mushrooms in paper towels and continued to squeeze them to remove as much liquid as possible. I’m continually amazed at the amount of liquid in mushrooms!
I heated a tablespoon of unsalted butter in a 10-inch skillet over high heat and added the mushrooms. After about 1 minute of stirring the mushrooms constantly, I added the Madeira and continued stirring the mushrooms until most of the liquid had evaporated. This took another minute or so. I removed the pan from the heat to allow the mushrooms to cool.
Finishing the Onion and Mushroom Tart in Puff Pastry:
I whisked the eggs and half-and-half together, and stirred in the onions and mushrooms. I poured the onion/mushroom mixture into the tart shell and placed it into a preheated 375°F oven for 25 minutes until the center felt firm to the touch.
After 25 minutes, the Onion and Mushroom Tart was perfectly cooked. I removed it from the oven, and let it cool for about 10 minutes before transferring it to a cutting board.
With its incredible onion flavor accented with an savory sautéed mushroom, the Onion and Mushroom Tart in Puff Pastry was absolutely delicious. Yum!
Onion and Mushroom Tart in Puff Pastry
- 1 sheet Puff Pastry, thawed
- 3 Tablespoons unsalted butter divided
- 1 1/2 pounds onions halved through root end, peeled, and cut crosswise into 1/4-inch slices (about 6 cups)
- 1/4 teaspoon dried thyme
- 3/4 teaspoon Kosher salt
- 1/4 teaspoon freshly ground black pepper
- 8 ounces fresh mushrooms coarsely chopped
- 2 Tablespoons Madeira
- 2 large eggs
- 1/2 cup half-and-half
- Preheat oven to 400° F.
- Roll Puff Pastry into 11 or 12-inch square on a floured surface. Transfer to 9-inch tart pan. Trim edges to within 1/2-inch, and fold edges into sides of crust. Place in freezer for 30 minutes. Place frozen tart shell on baking sheet. Dock with fork. Press crumpled piece of parchment paper down inside tart shell. Fill with dried beans or pie weights and bake until top edge just starts to color and surface of dough under parchment paper no longer looks wet, about 25 minutes. Remove from oven and carefully remove parchment paper and weights by gathering edges of parchment paper and pulling up and out. If cracks form in shell, brush with lightly beaten egg. Return baking sheet with tart shell to oven and bake until golden brown, 5 minutes. Set baking sheet with tart shell on wire rack. Cool completely.
- Heat 2 tablespoons of butter in 12-inch skillet over medium heat. Add onions, thyme, salt, and pepper. Cover and cook until onions for 15 minutes, stirring once or twice. Remove lid and continue to cook another 10 minutes. Remove pan from heat and let onions cool 15 minutes.
- Take mushrooms by the handful and squeeze to release liquid. Place in paper towels and squeeze again to remove as much liquid as possible.
- Heat remaining tablespoon of butter in 10-inch skillet over high heat. Add mushrooms; cook, stirring constantly until liquid evaporates, about 1 minute. Add Madeira and continue cooking over high heat until liquid evaporates, about 1 to 2 additional minutes. Remove from heat; cool.
- Whisk eggs and half-and-half together in large bowl. Stir onions and mushrooms into egg mixture. Spread onion mixture over baked crust (still on baking sheet).
- Bake at 375°F until center of tart feels firm to touch, 20 to 25 minutes.
- Cool on wire rack at least 10 minutes. When ready to serve, remove tart pan ring; gently slide thin-bladed spatula between tart pan bottom and crust to loosen, then slide tart to serving plate. Cut into wedges and serve.
- Yield: One 9-inch tart.