Rhubarb and Custard Tart

In my four years in London, I consumed exactly zero custard tarts. There were Bakewell tarts and natas and treacle tarts and Bea’s of Bloomsbury’s Townies — that’s brownie batter baked in a tart shell, for all the times when you’ve looked at a brownie and said, “This dessert needs a coat” — but never a real English custard tart.

Which is why it caught me by surprise when summer rhubarb appeared on every fruit stand and produce shelf and a voice in the back of my head that sounded oddly like Mary Berry declared that I needed custard tart with rhubarb, and I needed it now.

I’ve only come around to custards in the past two years. They always seemed fiddly and not quite worth the effort. Why temper egg yolks and stir on low for twenty minutes when a pudding requires exactly no egg-separating and comes together in five?

But custard tart feels greater than the sum of its parts somehow. The pâte sablée crust, in spite of its alarming French name, is far easier to work with than shortcrust, and aside from the less-scary-than-it-sounds moment when you temper the hot milk into the egg yolks, the custard leaves some room for error when you’re baking it. The rhubarb is beautifully tart against the creaminess of the custard, but you could easily switch it out for your favorite jam — raspberry would be lovely for the Fourth of July, especially if you sprinkled the custard with blueberries just before baking.

Even if you, like me, do a terrible job of trimming the tart shell after par-baking it or wind up slightly browning the top of the custard, once you’ve slid it out of the pan, it somehow still manages to look chic. What more can you ask of a custard-filled pastry?

Rhubarb and Custard Tart
Crust adapted from James Morton, custard adapted from Delia Smith and Dorie Greenspan

Rhubarb compote
1 pound rhubarb
¹⁄₄ cup granulated sugar
pinch of salt

Tart shell
2¹⁄₄ cups all-purpose flour
¹⁄₂ teaspoon table salt
3 tablespoons granulated sugar
5.5 ounces unsalted butter, cold
2 egg yolks, lightly beaten
5 tablespoons ice water

Custard filling
4 egg yolks
¹⁄₄ cup granulated sugar
¹⁄₄ teaspoon table salt
1 teaspoon vanilla extract
¹⁄₂ cup heavy cream
1 cup whole milk

1. For the compote: thinly slice the rhubarb, then toss with the sugar and salt. Cook in a saucepan over medium heat until the rhubarb slumps. Mash the fruit into a puree with a spatula, then cook until it thickens enough to hold a trail when you draw the spatula across the bottom of the pan. Set aside to cool completely.
2. Whisk together the flour, sugar, and salt.
3. Cut the butter into small cubes (half an inch or so), then rub the butter into the flour mixture until it resembles breadcrumbs.
4. Add the egg yolks to the butter-flour mixture and stir with a fork until it begins to clump together.
5. Add 3 tablespoons of ice water and stir again, then add up to 2 more tablespoons of water and stir with a fork until the dough comes together in one rough mass.
6. Turn the dough out onto a very lightly floured surface and knead it no more than two or three times, just to bring it together into a mass with no dry flour patches.
7. Wrap the dough in plastic wrap and rest in the fridge for at least 1 hour.
8. Once the dough has chilled, unwrap it and turn it out onto a very lightly floured surface and roll it out with a floured rolling pin. Keep the dough moving, rotating it ninety degrees every few rolls and periodically turning it over and flouring the counter beneath it. The final round of dough should be at least two inches larger than the base of your tart pan on all sides and be about a quarter inch thick.
9. Grease a 9- or 10-inch round nonstick, loose-bottomed tart pan.
10. Gently roll the round of dough back up onto the rolling pin, then begin unrolling it onto the tart pan beginning a little over an inch from the tart pan’s edge.
11. Once the round of dough is sitting on top of the tart pan, lift it by the edges and nudge it into the bottom edge of the pan, pressing it into the bottom and sides with your knuckle. Make sure the dough is flush with the pan on all sides.
12. Trim down the excess dough around the pan so there is about half an inch on all sides. Use these scraps of dough to patch any tears in the crust, then re-form them into a ball and return to the fridge.
13. Place the dough-lined tart pan in the freezer for 30 minutes. Preheat the oven to 380° F (190° C).
14. Once the tart shell has finished freezing, place the lined tart pan on a baking sheet. Prick the bottom of the tart shell all over (at least ten times) with a fork. Then butter a large piece of foil and press it on top of the crust, flush with the base and sides of the tart shell.
15. Bake the tart shell with the foil on top for twenty minutes, then remove the foil and bake for another ten minutes. (The tart shell should be lightly golden by now.)
16. Once the tart shell has finished its first bake, allow to cool for ten minutes before using a sharp serrated knife to trim the overhang off of the still-warm crust. Try to be as neat as possible, but don’t brush away any crumbs that have fallen into the tart pan until it’s fully cooled. If any tears have appeared in the crust during baking, use a thin layer of the reserved dough scraps to patch the hole while the shell is still warm. Cool the tart shell completely.
17. Turn the oven temperature down to 325° F (160° C).
18. For the custard, whisk the egg yolks with the sugar and salt in a large heatproof bowl until the sugar begins to dissolve, then whisk in the vanilla extract.
19. Heat the milk and heavy cream in a heavy-bottomed pot until they begin to steam, then turn off the heat.
20. Add about ¹⁄₄ cup of the hot milk mixture into the egg yolk mixture, whisking constantly. Then add another ¹⁄₄ cup and continue to whisk until uniform. Repeat this once more, then pour the rest of the hot milk and cream into the egg yolks, continuing to whisk until the mixture is completely uniform.
21. Pour the custard into any vessel with a spout to make filling the tart pan easier for you. If you want the smoothest custard possible, pour your custard mixture through a fine mesh sieve to catch any bits of cooked egg. If you find any of these in the sieve, do not push them through the mesh; just toss them out.
22. Evenly spread about 3 tablespoons of the rhubarb compote across the bottom of the fully cooled tart shell, which should still be on a baking sheet.
23. Open the oven door and set the baking tray with the tart shell on a middle rack, then pull out the rack halfway so you can reach the tart shell.
24. Pour the custard into the tart shell once it is inside the oven, leaving about half a centimeter of space at the top of the shell. There will be extra custard left over, so keep an eye on the shell as you pour.
25. Gently slide the rack back into place, taking care not to spill any custard. (If this method of filling the shell makes you nervous, you can do it on the countertop, but leave a little extra room at the top of the shell and move very carefully to avoid spills as much as possible.)
26. Bake the tart until the custard is set around the edges but still wobbles like jello in the center, about 18-22 minutes. If the custard sloshes like a liquid in the center of the tart, it’s not done yet, but make sure you start checking at the 18 minute mark to avoid a curdled custard.
27. Cool the tart in its pan for an hour. Unmold it and allow to cool on a cooling rack for at least another two hours or overnight in the fridge.
28. Serve sliced into dainty wedges alongside your favorite tea.

Tags: custard tart, fourth of july baking, halal baking, summer desserts, teatime bakes