📖 Instructions

1. First, let's get that butter pie crust going. In a large mixing bowl, combine the all-purpose flour, granulated sugar, and salt. Give it a good whisk to make sure everything's mixed evenly. You want to make sure your butter is super cold and cut into small, pea-sized pieces. Use a pastry blender or your fingertips to cut the cold butter into the flour mixture until it resembles coarse crumbs with some larger, lentil-sized pieces of butter still visible. This is super important for flakiness, so don't be tempted to overmix it!
2. Now, gradually add the ice water, one tablespoon at a time. Mix lightly with a fork or your hands until the dough just starts to come together. Be careful not to add too much water; you want it to be just moist enough to form a ball. If it feels too dry, add another half-tablespoon of water. Gather the dough into a disc, wrap it tightly in plastic wrap, and pop it into the fridge for at least 30 minutes. An hour is even better! This chilling time is vital for developing the gluten and making the dough easier to roll.
3. While your crust is chilling, it's time to prep the star of the show: the filling! Wash and trim the rhubarb stalks, then chop them into 1/2-inch pieces. For the strawberries, hull them and slice them into quarters or halves, depending on their size. You want pieces that are roughly similar in size to the rhubarb.
4. In a separate large bowl, gently combine the chopped rhubarb and sliced strawberries. Add the granulated sugar, cornstarch (this is our secret weapon for a thick, luscious filling that isn't watery!), lemon juice, and vanilla extract. Toss everything together until the fruit is well coated. The cornstarch will help thicken the juices as it bakes.
5. Once your dough is nicely chilled, preheat your oven to 400°F (200°C). Lightly flour a clean work surface and your rolling pin. Roll out the pie dough into a 12-inch circle, about 1/8-inch thick. Carefully transfer the dough to a 9-inch tart pan with a removable bottom. Press the dough gently into the bottom and up the sides of the pan. Trim any excess dough, leaving about a 1/2-inch overhang, and crimp the edges if you like for a pretty finish. If you want a lattice top, save half of the dough to cut into strips later.
6. Blind bake the crust: Line the tart shell with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes. This step helps prevent a soggy bottom, a common problem with fruit tarts! Remove the weights and parchment, then prick the bottom of the crust all over with a fork. Bake for another 5-7 minutes, or until the crust is lightly golden. Remove from oven and reduce oven temperature to 375°F (190°C).
7. Pour the prepared strawberry rhubarb filling into the warm, blind-baked crust, spreading it evenly. If you saved dough for a lattice top, now's the time to weave those strips over the filling. If not, just leave it as is for a beautiful open-faced tart. For a lovely golden finish, you can brush the exposed crust with an egg wash (one egg yolk mixed with a tablespoon of water) and sprinkle a little extra sugar over the crust edges.
8. Carefully place the tart on a baking sheet (to catch any potential drips) and bake at 375°F (190°C) for 50-60 minutes, or until the crust is deeply golden brown and the fruit filling is bubbly and tender. If the crust edges start to brown too quickly, you can gently cover them with aluminum foil.
9. Once baked, transfer the tart to a wire rack to cool completely. This is the hardest part, I know! Cooling allows the filling to set properly. Seriously, resist the urge to slice it too soon. It might be tempting, but trust me, it will be so much better if you let it chill out for a bit. Serve it warm or at room temperature, perhaps with a dollop of vanilla ice cream or a cloud of whipped cream. Enjoy every single glorious bite!