Here is a twist on a rhubarb custard pie recipe that is spectacular for two reasons, and both concern the creamy and sturdy custard that takes center stage. For this pie, the custard is first prepared with the rhubarb added at the beginning of the process so that any liquid the plant releases becomes part of the finished product. Then the pastry cream is baked for a second time between two layers of flaky, buttery pastry to enhance the flavor and solidify the filling so that it slices beautifully. Almonds may be substituted for an even more subtle nutty aroma, but do make sure to include the nut meal as it brings a welcome richness and depth of flavor to the whole party.
Rhubarb Custard Pie
1 recipe for a double crust pie pastry (2 discs pie dough)
3 cups chopped fresh or frozen rhubarb
1 ½ cups light brown or golden yellow sugar, packed
5 tablespoons unbleached all-purpose flour
1 cup whole milk (3.5%)
1/8 teaspoon fine table salt
4 large egg yolks
1 teaspoon pure vanilla extract
½ cup hazelnut meal (roasted and finely ground)
1 teaspoon water
course sugar for sprinkling
1. Make the custard.
To make the custard, combine the rhubarb, sugar, flour, salt, milk, egg yolks, and vanilla extract in a large metal bowl. Create a double boiler by filling a medium pot with a few inches of water and placing the metal bowl containing the ingredients over top, ensuring that the water does not touch the bottom of the bowl. Set the pot over medium-low heat and bring the water to a simmer, stirring the ingredients frequently with a whisk or a heat-proof spatula.
As the water continues to simmer and the custard begins to cook and thicken, focus on scraping the bottom of the bowl with the spatula and stirring constantly to prevent the mixture from curdling. When the custard reaches 180° F on an instant read thermometer, or is thick enough to coat the back of a spoon, immediately remove the bowl from the heat and continue to stir for a minute until it begins to cool. Place a piece of plastic wrap on the surface of the custard and allow it to cool to room temperature, then chill it in the fridge for at least four hours to allow the custard to become firm.
At this point the custard may be stored in the fridge for up to 24 hours.
2. Assemble and bake.
When you are ready to bake the pie, roll out one disc of pastry and fit it into a 9” pie plate, leaving at least an inch of overhang to be trimmed after the top pastry is arranged. Place the shell in the freezer for several minutes to re-chill the dough. Roll out the second disc of pastry into a large circle slightly thinner than that of the shell, and cut it into 2” wide strips. Place the strips in the freezer for several minutes to re-chill the dough. The goal is for the pastry to be cold, but flexible enough so that you may shape the edges.
Remove the pie plate from the freezer and carefully pour the chilled custard into the shell. Cover the entire surface evenly with the strips of pastry, making sure that they do not overlap to allow for ventilation and trimming the edges where necessary. Curl the shell overhang up over the circle of pastry, trimming where necessary, and press it into a fluted edge. Carefully place the whole pie in the freezer for 20 minutes, ensuring that it is sitting level. While you are waiting for the dough to chill, preheat the oven to 400° F.
Whisk together the egg and teaspoon water. Gently place the pie on a sturdy baking sheet and brush the top with the egg wash, then sprinkle sugar over top. Bake in the preheated oven for 50 minutes to 1 hour, or until the top pastry is golden brown and slightly puffed. Use a pie shield if necessary to protect the edges from over-browning during the last 20 minutes of baking.
Allow the pie to cool to room temperature and chill before serving, at least 4 hours. This will ensure that the pie will slice cleanly. Store the pie in the refrigerator, and serve it slightly chilled or at room temperature the next day.