Strawberry Rhubarb Slab Pie

Young rhubarb harvested from my community garden.

I am not made for this digital age. I cook ALL THE TIME, but rarely do I remember to take photos of my food, since I’m usually in the process of serving it. My friends like what I cook and we are happy to enjoy a meal amongst ourselves, without broadcasting to others. I say this to explain why I this recipe for a truly stunning summer pie has no accompanying picture.

Slab pie is a crust-lover’s dream. Imagine a bar cookie with a 1/2-inch of fresh filling sandwiched between two pieces of flaky dough. Slab pies cut cleanly, can be picked up neatly, and feed a crowd.

Strawberry and rhubarb make an exceptional filling, as long as you manage their juices. In this recipe, I do that two ways: 1) Macerate the cut fruit overnight and then reduce the released juices to a syrup and 2) Use cornstarch to thicken the filling as it bakes.

6 - 7 cups cut strawberries (1/2-inch pieces), about 2 pounds
8 cups cut rhubarb (1/2-inch pieces)
3 1/2 cups sugar
1/2 teaspoon salt
3 sprigs fresh thyme or 1 small branch of rosemary
1/4 cup strawberry or apricot jam (optional)
1/2 lemon
3 tablespoons corn starch
full recipe (2 pieces) of butter pastry dough, each rolled to the width of a 1/2 sheet pan
1 egg, very well beaten
sanding sugar

Combine strawberries and rhubarb in a large bowl and toss with the sugar and salt. Let sit overnight, or at least up to 6 hours. The fruit will have released a great deal of juices. Strain the fruit, capturing the juices, then transfer the juices to a small pot. Add the herbs. Place over medium-low heat and reduce the juices about halfway, until thickened enough to coat the back of a spoon. Let these juices cool completely before using. Meanwhile, dock the bottom slab of pastry dough with a fork. If you are using a lattice top, cut and design your lattice now. Keep the pastry cool in the refrigerator until ready to use.

Preheat the oven to 400 degrees F. Move a rack to the bottom of the oven. That’s where you’ll place your pie to bake.

Add the cooled syrup, jam, lemon, and cornstarch to the bowl of berries. Toss well and pour out onto the bottom piece of chilled pastry. Spread the berries evenly over the pan, making sure to cover the corners. Place the other piece of dough or the lattice design on top and press the edges together to seal. If using a whole piece of top dough, cut 3 or 4 slits through it to let steam escape from the soon-to-be-bubbly fruit.

Brush the beaten egg all over the dough, including the edges. Top the brushed pastry with a generous amount of sanding sugar. Place on the bottom shelf of the oven. After 25 minutes, turn the tray. Check after 25 more minutes. The crust should be browning and the fruits should be bubbling. Continue to cook the pie until the crusts are deep brown, but not burned, maybe another 10 minutes more. This insures that the bottom crust is actually done.

Pull the pie from the oven and let the tray cool on a wire rack for at least 2 hours to set. You can serve it directly from the pan, or, once cooled and set, cut into pieces to place on a platter.

Store at room temperature wrapped well for up to 3 days.