Savory, hearty and suffused with the slightly sweet flavor of caramelized butternut squash and leeks, I created this tart to compliment the main course for my good friend Danielle's birthday celebration (we won't say what birthday)! Danielle is a master griller and while I do not believe anyone should cook on their own birthday, I do understand her desire to share her gifts with those she loves on her special day.
She was making this Smoked Chilean Sea Bass recipe. It is full of the pungent spices flavors of a blackened rub balanced by bright citrus and smoke. I thought the savory and sweet notes of butternut squash would compliment it nicely and since we still had four of the winter squashes from our summer garden it seemed like the perfect fit.
It was a nice compliment to the meal and the dinner guests took all the leftovers home.
To shape the tart I used a 9 inch spring form pan. We served 6 people and had leftovers for another 4-6 people. If you were using a traditional tart shell I believe this recipe would make 2 complete tarts.
Cheddar Cayenne Crust
If you have not put your butter in the freezer yet do it now. The more cold it is the better. I keep mine in our deep freeze. If you don't have a good heavy knife cut the cheese first and then put it in the freezer.
For the crust, start by shredding 4 ounces of a quality cheese from the sharp cheddar family. I choose Kerrygold's Dubliner. I use a medium grate because I want the cheese distributed throughout the crust without any chunks.
Put the flour salt and cayenne in a large food processor pulse it quickly to give it a quick mix.
Next add the cubed butter and pulse on high until the butter begins to combine and the flour begins to look like coarse crumbs.
Add the cheddar cheese and continue to pulse until the flour and cheese are fully incorporated. This is a lot of pastry crust so I recommend scraping it into a large bowl to mix in just enough ice water for the contents to come together into a dough.
I have had success with a very large food processor bringing the crust together into a cohesive ball, but not often.
Take 1/2 half the ball of dough and role it out about 1/8 and inch thick on parchment paper dusted with flour. Make sure the dough is larger than the 9' spring form pan.
Place the spring form pan upside down on the rolled crust and press down firmly to cut through the dough. Lift the springform pan and trim the excess dough from around your circle of dough.
It's tricky, but leaving the circle of dough on the parchment paper slide the bottom of the spring form pan under the dough and paper so that it lines up with the circle. Carefully snap the sides of your spring form pan in place.
Walla! You have a bottom crust that is of a consistent thickness that will come off of the springform nicely for serving.
Roll out sections of the remaining dough to 1/8 thickness and cut them into about 4 inch strips. Press them along the sides of the pan to form the side crust. Make sure the pieces of crush seal together and with the bottom crust. Use a tough of water to help seal if necessary.
When complete you should have your 9' pan sealed with a nice flavorful crust of fairly uniform thickness. Set aside while you make the filling.
I used one large leek: greens and whites. I don't know why so many people throw away the green parts. They taste wonderful and just take a touch longer to cook.
Cut the roots off the leek and split it down the middle. Make sure you was the leek once its split they almost always hold dirt and sand down in the layers of leaves.
Once cleaned chop the greens and put them in a bowl, then chop the remaining whites and put them in a separate bowl
My 1 leek provided me with about 5 cups of chopped goodness. You will want about the same amount to fill your tart crust.
Next prepare your butternut squash. Use a sturdy sharp knife and split the squash down the middle, remove the seeds with a large spoon and lightly scrape the seed cavity.
Peel the squash with a vegetable peeler. With butternut you may see a lighter whitish area under the rind. If you prefer you can peel all this away until you are down to the bright yellow. Occasionally there will be green veins under the rind. I peel away the green veins but do not worry about getting down to the bright yellow.
Dice squash into the size chunks you would like in your tart. I prefer about a 1/4 inch dice.
My squash totaled about 7 cups once prepared. That was perfect for the 9' springform pan.
Now it's time to get cooking. I used a 8 quart dutch oven, but you can use any large pot or sauté pan.
Melt the butter over medium high heat and add 2 tablespoons of the olive oil. Once the butter begins to sputter add the green leek parts. Saute for 5 mintues until the green parts are softened.
Next add the leek whites and continue to cook for another 5 minutes on medium high heat. You want to continue cooking until you see some of the chopped leek is browning. Caramelized leek flavor is amazing.
Once that is done, use a slotted spoon to transfer the leeks to a large bowl keeping as much oil as possible in the pan.
Add the last two tablespoons of olive oil and fry the julienned sage for a minute or two and then add the thyme and black pepper.
The sage should begin to crisp up. When it does use the slotted spoon to transfer it to the bowl with the cooked leeks.
Crisping the sage mellows the flavor but we don't want it to burn, watch is carefully.
Next add the 7 cups of squash to the pan. Fry in the oil for 10 minutes stirring occasionally and scraping the bottom. Browning on the bottom of the pan and the squash is what you want.
Next use the chardonay to deglaze the pan scapeing any carmelization from the bottom.
Quickly put on the lid and reduce the heat to low and let the squash steam until it is cook all the way through but not mushy. With my dutch oven that was 5 mintues.
Preheat your oven to 350 degrees Fahrenheit.
When the squash is done, gently transfer it to the bowl where the leeks and sage have been cooling. The chunks will the soft on the edges so we don't want to break them apart or be mashed.
While the filling cools, shred your gouda cheese. For this I use a coarse grater because I want there to be strings and pockets of delicious cheese tucked away throughout the tart.
Take the eggs, cream and the chicken broth from the refrigerator. Pour the chilled cream over the squash to help cool it. It only has to be cool enough so that the eggs don't cook.
Add the truffle oil.
Wisk the broth and eggs together and pour the chilled liquid into the vegetable mix. Gently mix it all together until the ingredients are distributed evenly.
Remember we are trying to keep the butternut chunks whole so don't overdo the mixing.
Salt to taste. Everyone is different here, but i used 1 teaspoon.
Once combined pour the filling into the tart crust. If you used the same amounts as me it should come to the very top.
Carefully transfer it to the middle rack of your preheated oven and bake it for 30 minutes uncovered.
(Optional Step - but still cook additional time - good if there is excess liquid from veggies)
At 30 minutes open the oven and lightly sprinkle the top of the tart with bread crumbs. It should be a light coating where you can see hints of the squash and leek beneath it.
Cook for another 20 minutes checking after 10 to make sure the top is not overbrowning.
When the time is up, open the oven and wiggle the tart pan. The center of the tart should be firm.
Remove the tart from the oven and let it cool for 10 - 15 minutes. I will still be warm enough to serve.
My crust is almost always separated from the sides of the spring form pan, but if you are not sure run a thin knife around the edges of the pan to make sure the crust is free from it.
Place your serving platter next to the tart. Release and remove the sides of the springform pan. Use the parchment paper to slide the tart off the bottom of the springform pan and onto your serving plate.
Next, gently hold the tart in place and pull the parchment paper out from under the tart. Your creation should be whole and intact... ready to garnish and serve. I drizzled the top with a small amount of additional truffle oil.