Friday, August 13, 2010
Blackberry Lemon Tart
It's amazing how much bounty we have right at our fingertips if we know where to look. For an aspiring urban forager in the Pacific Northwest, August means blackberry season. There are brambles all over the city--tucked in forgotten corners, on unwanted strips between sidewalks and malls, and blanketing hillsides on steep Seattle streets.
My first blackberry hunting trip of the season was with Langdon Cook, an expert local forager who taught a session of my Art of Food class. Our adventure took us mere blocks from Cornish, in the middle of downtown Seattle. A patch of blackberries stretched above us from the otherwise empty, clean city sidewalk to the pay-to-park lot above. There weren't many ripe berries at eye level--it was the beginning of the season and most were still pale green or blush pink. But the real treasure lay off the beaten path. I saw a way to climb up the hill: long grasses and a bit brambly, but doable. I silently thanked the universe for the fact that I'd worn pants on that sunny summer day, but muttered some curses for not thinking of tennis shoes as well. My feet sweat and slid out of my flip flops. I considered going barefoot for a moment and decided that was an even worse idea as the thorny bushes surrounding me were almost certainly part of the dead stuff below me. Sandals would have to stay. I found footholds one at a time, bracing my toes against the single strap keeping my foot in my shoe, and kept picking.
By the end of half an hour or so, I had nearly filled the old quart-size yogurt container that was acting as my berry bucket. I had a few scrapes and a bit of itchy berry fluff between my fingers and toes, but overall no real damage. Totally worth it.
Now, the question of what to make. With just under four cups, I didn't have quite enough berries to make a crumble or a pie without mixing them with another fruit. Peaches would be nice, but I can't seem to hold on to stone fruit for more than a day or so without eating every bit in sight. So I didn't have any. What I did have, though, were lemons. Lots and lots of lemons, left over from a party the week before. I imagined a tart with a lemon bar-like filling and topped with a thick sweet layer of cooked blackberries, and once I had that image in my head I couldn't let it go.
So here it is. I used the tart dough from Smitten Kitchen (easy! unshrinkable! no pie weights!), the lemon layer from my mom's recipe for lemon bars, and the blackberry layer from my own experience in making jam. And oh my, it's delicious. Supported by a strong buttery crust, creamy and tart on the inside, and jammy sweet on top with a slight crunch of blackberry seeds for an interesting texture.
Although this tart is well-balanced and summery as is, you could easily switch out the flavors of the layers and still use the same techniques. Perhaps use lime instead of lemon or raspberries instead of blackberries. I could even see incorporating minced herbs into the crust, perhaps to complement a strawberry topping. Don't be concerned about making three components. It may look impressively fancy, but it's actually a rather simple tart.
Blackberry Lemon Tart
For the dough:
1 1/2 cups flour
1/2 cup powdered sugar
1/4 teaspoon salt
9 tablespoons very cold (or frozen) butter, cut into small pieces
For the lemon filling:
1 cup sugar
3 tablespoons lemon juice
1 tablespoon lemon zest
For the blackberry filling:
3-4 cups blackberries (if you're foraging these, feel free to use the more tart reddish berries that are not quite fully black. They'll all cook down together happily.)
1 cup sugar
1. Make the dough.
Pulse flour, sugar, and salt in a food processor. Add chunks of butter and pulse until coarsely cut in. You should have butter pieces about the size of small peas. Stir the egg and add to the dough a little at a time, pulsing between additions. The mixture will look granular and odd--don't despair. Turn on the food processor in long pulses, about 10 seconds each, until the dough comes together in clumps and chunks. The sound of the food processor will change just before the dough is ready. Turn the dough out onto a work surface and briefly knead just enough to get all the dry ingredients worked in. Flatten to a rough disk and transfer into a 9-inch tart pan. Push the dough around with your fingers or palm until it covers the whole pan, including a thick layer on the sides. Make sure the crust is at least a 1/4 inch thick in all places, and that it's not too thick on the edges where the pan's wall connects to the bottom. Pierce all over with a fork and freeze at least 30 minutes.
2. Bake the crust.
Preheat the oven to 375 degrees. Butter the shiny side of a piece of aluminum foil and tightly press butter side down into the frozen tart shell. (Since you froze the crust, you can bake it without pie weights. This is genius.) Bake for 20-25 minutes. Take the tart out of the oven, remove the foil, and gently push the middle down with the back of a spoon if it's rising up. Return to the oven to bake for another 5 minutes.
3. Make the lemon filling.
While the crust is baking, combine the eggs, sugar, lemon juice, and zest and mix well. When the crust has finished its last 5 minutes, immediately pour the lemon filling on top. Carefully return to the oven and bake 25 minutes, or until lemon layer is set and firm.
4. Make the blackberry topping.
While the crust and lemon layer are baking, combine blackberries and sugar in a small pot on the stove. Cook on medium heat, stirring occasionally, until the berries are broken down and the mixture is thick. You're looking for something in between a sauce and a jam consistency, because it will thicken slightly as it cools. When the lemon layer has finished baking, pour the blackberry goo on top and spread carefully.
Cool tart on a cooling rack and then refrigerate at least one hour. Cut slices with a sharp knife and serve cold or at room temperature.