The most difficult part about using rhubarb as a pastry filling is that once it’s cooked it has almost no structure. Actually it’s entirely liquid. For this reason rhubarb is often mixed with other fruit like strawberries or apples. Right now I have lots of rhubarb, hardly any fruit in the freezer, and berries and apples are still months off. In other words I have to set my rhubarb filling with gelatin or cornstarch.
We like rhubarb because it is tart, but oftentimes it is too tart. To make sure the acidity isn’t overpowering, I make rhubarb pie in a shallow, French tart pan instead of a classic North American pie pan; this way there is a higher pastry to filling ratio. And I make sure to temper the acidity of the rhubarb with the proper amount of sugar in the filling, and possibly even some coarse sugar baked onto the surface of the pie. Ice cream also helps.
- 1 kg rhubarb, fresh or frozen (this is more rhubarb than you’ll need to make one pie, but I like to make lots and eat the excess with granola and yogurt, or make crumble)
- 200 g granulated sugar
- 60 g cornstarch
- 700 g short pastry
- Cook the rhubarb and sugar in a pot over medium high heat, until the rhubarb has broken down. Add the cornstarch, return to a boil. Pour into a tray and let cool. Test consistency and adjust accordingly.
- Roll out pastry to 1/8″. Line the tart shell. Add the rhubarb filling. Add top pastry in lattice.
- Bake at 425°F on a low rack for 15 minutes, then at 350°F until the pastry is golden brown, cooked through, and the filling is just starting to bubble, roughly another 25 minutes. Tastes like springtime.