Rhubarb & Custard Tart
Rhubarb and custard is a classic early spring combo. We roast the rhubarb separately so it caramelizes and retains its shape. Adding a little buckwheat balances the tart pastry with a pleasant nuttiness. Plus rhubarb and buckwheat are family members, so the pairing feels just right.
Serves 10
INGREDIENTS
For the tart pastry
175 grams all-purpose flour
50 grams buckwheat flour
20 grams sugar
½ teaspoon salt
150 grams unsalted butter, chilled and cubed
1 egg, beaten
1-2 teaspoons water (if needed)
For the rhubarb
1 ½ pounds (680 grams) rhubarb, cut into 2-inch pieces
10 cardamon pods, lightly bashed
⅓ cup sugar
1 orange, zest only (use a vegetable peeler)
For the custard
475 grams heavy cream
250 grams whole milk
100 grams sugar
¼ teaspoon salt
1 vanilla bean (see note)
9 egg yolks
METHOD
Preheat the oven to 450°F with the fan on.
Make the pastry. Mix the flours, sugar, and salt in a mixing bowl or food processor. Work the butter into the mixture until the dough resembles breadcrumbs (or wet sand). Stir in the egg and just enough water to form a smooth dough. Wrap tightly and refrigerate for 30 minutes and up to 1 day.
Roast the rhubarb. Toss together the rhubarb, sugar, cardamom, and orange zest and arrange in a single layer on a parchment-lined sheet pan. Roast for about 20 minutes, until the rhubarb has caramelized. This can be done up to 1 day in advance.
Blind bake the pastry. Lower the oven temperature to 350°F. Lightly grease a deep 10-inch tart pan. Roll out the pastry on a lightly floured surface to ¼ inch thickness. Drape it over the back of the rolling pin and transfer to the tart pan. Evenly press the pastry into the pan and trim any extra. Prick the bottom of the pastry with a fork and freeze for 30 minutes. Cover the tart with parchment paper and fill with a pint of dried beans (or rice). Bake for 20 minutes. Remove the paper and beans and bake for another 10 minutes, until well browned.
Make the custard. While the pastry is baking, gently bring the milk, cream, sugar, salt, and vanilla to a simmer. Turn off the heat and allow the vanilla to steep for 5 minutes. Whisk the egg yolks in a mixing bowl, then slowly whisk in the cream mixture. Add the cream very slowly at first, gradually increasing the speed after a cup has been added. The goal is to raise the temperature of the eggs gradually enough so they don’t curdle.
Bake the tart. Lower the oven temperature to 250°F. Strain the custard through a sieve into the baked tart shell. Place on a sheet pan and carefully transfer the tart to the oven. Bake until the custard is set but there is still a slight wobble, about 60 minutes.
Serve. Decorate the tart with the roasted rhubarb and serve. The tart can be served warm or cold. You’ll be able to decorate the tart more easily and neatly if both it and the rhubarb have cooled completely. Regardless, it will be delicious.
Note: Vanilla beans are expensive, so we like to get as much flavor out of them as possible. After steeping in the cream, rinse the bean off and dry it in a dehydrator or low oven. You can now use the bean to flavor sugar, maple syrup, or steep in a few ounces of bourbon to make your own vanilla extract.
FURTHER READING
