My, oh my, this is good one! The combination of rhubarb and thyme in this tart is sooo good. It’s a pairing that I know seems a bit odd. I wasn’t all that sure myself- rhubarb & thyme? But trust me, once you bake this and then dig into it, you’ll understand. It totally works.
The young rhubarb (which was freshly picked from my garden) is tangy & tart. When roasted, like in this recipe, it becomes even more fragrant and more intense with that unique “rhubarb-y” flavor. The lemony and earthy notes of the English Thyme add a nice depth to both the crust and final topping. The zing of the Granny Smith apple I used keeps with the tart theme (ha! see what I did there) but lends just enough sweetness to tie it all together. Viola! Heaven on a plate. Or well, getting pretty darn close. There are a few steps to making this, but none of them are hard. The end result is worth it!
For the crust (Pâte Brisée):
2 cups all-purpose flour, sifted
1/4 cup sugar
1/2 teaspoon dried thyme
pinch of salt
1/3 cup unsalted butter, cold and diced into small pieces
1 large egg
4-6 tablespoons of ice water
9.5 inch tart pan with removable bottom
Add flour, sugar, thyme, and salt to medium size bowl. Rub in the butter with your fingers until the mixture resembles fine bread crumbs. Work quickly to keep the butter chilled. Add the egg and enough water to bring it to a soft dough. Knead the dough on a floured board only long enough to bring it together to form a round. Cover with plastic wrap. Let the dough rest in the refrigerator for at least 30 minutes, even better, overnight. After chilling, allow 5-7 minutes to come back to room temperature before working with it.
Roll out on a floured board to approximately 11-inch round. Fit into a 9.5 inch removable bottom tart pan. Carefully push the dough into all edges of the pan. To trim top, slide the rolling pin over the entire top of pan. This will quickly and neatly remove the excess dough, leaving you with a nice clean edge. Chill in fridge until ready to assemble tart. Or you can pre-bake the tart blind for about 8-10 minutes at 350F to reduce the overall cooking time.
For the roasted rhubarb / fruit prep:
10-15 stalks rhubarb, cut into small dice. Enough to yield 1-1/2 cups
1/2 cup sugar
1 granny smith apple, cut into small dice
Preheat oven to 400F. Line a standard baking sheet with foil. Trim leaves from rhubarb and discard. Wash stalks well, then cut into small dice. Place on baking sheet and add sugar. Gently mix sugar throughout the pan. Bake for 15 minutes or until just tender (al dente). Allow to cool before adding to tart. Cut apple into small dice. Keep chilled until ready to assemble tart.
For the custard filling:
2/3 cup sugar
2/3 cup light cream
2 large eggs
3 tablespoons milk
Whisk all the ingredients in a medium size bowl until custard has become light and frothy.
To Assemble & bake tart:
Preheat oven to 350F. Line a standard baking sheet with foil. Add the roasted rhubarb and apples to the chilled dough in tart pan. Slowly pour the custard filling over all of the fruit, approximately 1 cup. You may not need all of it, so keep an eye on the fill-level of the tart as you go- don’t overfill. Place on baking sheet and carefully move to middle rack of preheated oven. Bake at 350F for 40-45 minutes or until cake tester comes out clean from middle of tart. Depending on oven calibrations, you may need to bake a little longer. If so, cover tart with foil when it starts to brown and keep a close eye on it. Allow to cool before removing from tart pan. Garnish with fresh thyme leaves and confectioner’s sugar (optional).