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Potato Mushroom Tart

This potato mushroom tart recipe is from the cookbook, Gluten-Free Girl and the Chef

Author Shauna James Ahern notes:

Almost everybody loves mushrooms, but most people think mushrooms mean button mushrooms or those god-awful mushrooms from a can. If you haven’t experienced anything but those, then portobello, or shiitake, or cremini mushrooms can seem like wild mushrooms.

But true wild mushrooms live in the forests. And luckily for us, at the farmers’ markets. Lobster mushrooms, cauliflower mushrooms, morels, hen of the woods, matsutakes, black trumpet mushrooms in the winter. There are so many to explore.

Making this tart gives you the chance to explore. We’ve specified portobello mushrooms for this recipe, only because we know that folks outside of the Pacific Northwest don’t have the easy access to wild mushrooms that we do. Feel free to substitute any mushroom that is in season.

Mushroom tarts are standard in classical French cuisine. But I love mushrooms and potatoes together, from their connection of having been raised in the earth.

Potato Mushroom Tart - www.cooksandbooksandrecipes.com

Potato Mushroom Tart
Photo credit: Lara Ferroni

Cooks&Books&Recipes Editors’ Notes:

I hope Shauna and Danny will forgive me, but since I don’t follow a gluten-free diet and since I’m not a baker, I used prepared puffed pastry sheets for the tart shell. (I would love to get feedback/comments on this tart recipe from gluten-free cooks.) The wild mushrooms (we used morels, cremini, and portobello), heavy cream, and fresh herbs turned this weekday, made-at-home meal into a decadent, chef-quality splurge.


Potato-Mushroom Tart

Featured Recipe From: Gluten-Free Girl and the Chef: A Love Story with 100 Tempting Recipes

Yield: Feeds 8 to 10


  • 3 to 4 large portobello mushrooms
  • 4 tablespoons extra-virgin olive oil
  • Kosher salt and cracked black pepper
  • 2 cups heavy cream
  • 10 cloves garlic, peeled, 6 of them smashed and 4 thinly sliced
  • 2 teaspoons finely chopped fresh rosemary and thyme combined, stems set aside
  • 1 bay leaf
  • Small pinch freshly grated nutmeg
  • 3 large eggs
  • 2 cups thickly sliced button mushrooms
  • 3 shallots, peeled and thinly sliced
  • 1/2 white part of 1 leek, thinly sliced
  • Kosher salt and cracked black pepper
  • 1 Tart Shell, unbaked, in a tart shell pan (recipe below)
  • 3 medium russet potatoes, peeled and grated, squeezed to remove excess water
  • 1/4 cup freshly grated Parmesan cheese


  • 1/2 cup (63.5g/2.2oz) sorghum flour
  • 1/2 cup (60g/2 oz) tapioca flour
  • 1/2 cup (96g/3.4 oz) potato starch
  • 1/2 cup (102g/3.4 oz) sweet rice flour
  • 1/4 teaspoon salt
  • 8 tablespoons (1 stick) frozen butter
  • 1 large egg
  • 1/4 cup ice-cold water
  • Butter for greasing pan


Preparing the portobellos

Preheat the oven to 450°F. Stem the portobellos and remove the gills. Toss with 2 tablespoons of the oil and some salt and pepper. Place on a baking sheet and bake the mushrooms until they are sizzling and beginning to wilt, 5 to 6 minutes.

Heating the cream

Combine the cream, the smashed garlic cloves, 1/2 teaspoon each of salt and pepper, the stems of the rosemary and thyme, the bay leaf, and the nutmeg in a large saucepan over medium heat and cook, stirring, until the cream boils. Take the pan off the heat and allow the cream to steep for 2 to 3 minutes.

Tempering the eggs

In a bowl, whisk the eggs together. Pour 1/2 cup of the cream mixture into the eggs, whisking continuously. When that mixture is fully combined, slowly pour the remaining cream mixture into the eggs, whisking continuously. Pour the custard through a strainer and set it aside.

Sauteing the mushrooms

Set a large saute pan over high heat and pour in the remaining 2 tablespoons of oil. Toss in the button mushrooms. Cook, stirring occasionally, until they have a good brown color, about 5 minutes. Add the shallots, leek, and sliced garlic and cook, stirring, until everything is softened and translucent, about 5 minutes. Toss in the chopped rosemary and thyme and cook until they release their fragrance, about 2 minutes. Stir everything up. Season with salt and pepper. Set aside to allow the mushrooms to cool.

Blind bake the tart shell at 375°F (see recipe below). Keep the oven on after the shell is baked.

Combining everything together

Combine the mushroom mixture and the custard. Toss in the potatoes and Parmesan cheese and mix to combine. Season with salt and pepper.

Baking the tart

Pour the mushroom and custard mixture into the prebaked tart shell. Carefully arrange the portobellos in a circle in the middle of the tart shell. Bake until the center of the tart is set, 35 to 40 minutes. Poke the custard in the center of the tart with a sharp knife, through the portobellos; the knife should come out clean. You should be able to jiggle the pan and not see any movement, and the tart should be tanned, but not entirely browned.

Cooling the tart

Take the tart out of the oven and let it cool in the pan on a wire rack until it has reached room temperature, about 1 hour. Remove the outer ring from the tart shell pan before serving.


You could use any fresh mushrooms you want here, but dried mushrooms will be a disappointment. You could try a Gruyère cheese instead of the Parmesan, and Manchego or pecorino would be great too.


You could make this as an appetizer. Or serve it with a nice little salad for a summer lunch, with a little balsamic vinaigrette or reduction sauce.

Combining the flours for the tart shell

Sift the sorghum flour, tapioca flour, potato starch, and sweet rice flour into a large bowl. Stir in the sugar, salt, and cinnamon. Sift into another bowl.

Grating the butter

Grate the frozen butter directly into the dry ingredients. The butter will fall into the flours in soft swirls and start to melt in as soon as you stir. (Hint: this works well with traditional tart doughs too.) Work with your hands to mix everything, until the dough feels like cornmeal or large pieces of sand.

Finishing the dough

In a small bowl, whisk the egg and water together with a fork. Make a well in the center of the flours. Stir in the liquid, working from the inside out. Feel the dough for soft suppleness, in-stead of stiffness or sogginess. Feel free to use your hands at the end.

Chilling the dough

Refrigerate for at least 1 hour, or overnight if possible.

Preparing to bake the tart shell

Preheat the oven to 375°F. Butter and flour an 11-inch tart shell. (We like sweet rice flour for this.) Pull the dough from the refrigerator and let it come to room temperature, about 1 hour.

Rolling out the dough

Roll out the dough between 2 pieces of parchment paper, to the approximate shape of the tart pan. (This saves you flouring the countertop, and thus adding more flour to the dough.) If the dough breaks apart a bit, do not worry--there's no danger of the crust becoming tough by overworking it, which could happen in a gluten dough. Press the dough into the pie pan and repair it that way.

Freezing the tart shell

Place the tart shell in the freezer until the crust is frozen, about 1 hour.

Blind baking the tart shell

Butter a piece of aluminum foil approximately the size of the pie crust. Place it, butter side down, onto the tart crust and fit snugly against the sides. Bake, pressing down any puffed-up portions with a spoon, until the shell has a good color, about 15 minutes. The tart should feel flaky, rather than sticky.

© 2010 Shauna James Ahern and Daniel Ahern

Reprinted with permission from Gluten-Free Girl and the Chef: A Love Story with 100 Tempting Recipes, by Shauna James Ahern and Daniel Ahern (John Wiley & Sons)

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