Ingredients

• 2 3/4 cups all-purpose flour
• 1 teaspoon salt
• 2 tablespoons granulated sugar (for crust)
• 1 cup (2 sticks) cold butter, cut into pieces
• 1/2 cup, plus more as needed ice water
• 1 pound (about 4 cups) rhubarb, cut into 1/2-inch pieces
• 1 pound (about 4 cups) strawberries, hulled and halved
• 3 tablespoons cornstarch
• 3/4 cup granulated sugar (for filling)
• 1/4 teaspoon ground cinnamon
• 1 teaspoon lemon juice
• 2 tablespoons unsalted butter, cut into small pieces
• 2 tablespoons milk, for brushing
• about 1 tablespoon granulated sugar, for sprinkling

Equipment

• Food processor
• 9-inch pie pan
• Rolling pin
• Pizza cutter or pastry wheel
• Baking sheet
• Wire cooling rack

Instructions

1. Make the crust: In a food processor, pulse the flour, salt, and 2 tablespoons sugar until combined. Add the cold butter and pulse until the mixture looks like coarse crumbs, about 15 seconds, which gives you a flaky, not greasy, dough.
2. With the machine running, pour in 1/4 cup ice water in a slow stream until the dough just holds together when you pinch it. Add a splash more if needed, but stop within 30 seconds so the crust stays tender.
3. Turn the dough out, gather it into a ball, and divide in half. Flatten each half into a disk, wrap in plastic, and chill for about 1 hour. This firms up the butter and relaxes the gluten so the crust rolls out easily.
4. Roll the first disk on a lightly floured surface into a 12-inch circle, turning it a quarter turn as you roll to keep it even and unstuck. Fold it in half, lift into a 9-inch pie pan, and trim the overhang to about 1/2 inch. Cover and refrigerate while you work.
5. Roll the second disk into a 13-inch circle and cut it into 3/4-inch strips with a pizza cutter or pastry wheel. Lay the strips on a parchment-lined baking sheet, cover, and chill about 10 minutes so they stay firm and easy to handle.
6. Make the filling: Put the strawberries and rhubarb in a large bowl. In a small bowl, stir together the cornstarch, 3/4 cup sugar, and cinnamon until evenly blended.
7. Take the pie shell from the fridge and sprinkle about 2 tablespoons of the sugar mixture over the bottom, which helps soak up juices so the crust doesn't get soggy. Toss the rest of the sugar mixture with the fruit, then pour it into the shell. Drizzle with the lemon juice and dot with the 2 tablespoons of butter.
8. Weave the lattice: Lay half the strips across the filling about 1 inch apart, longest in the middle. Fold every other strip halfway back, lay a strip perpendicular across, then unfold. Repeat with the alternate strips, adding perpendicular strips until the top is woven.
9. Trim the strips to a 1-inch overhang, tuck the ends under the bottom crust, and flute the edge to seal. Brush the lattice with milk and sprinkle lightly with sugar for a golden, crisp finish. Chill while the oven heats.
10. Preheat the oven to 400 degrees F with a rack in the lower third. Set a foil-lined baking sheet on the rack to catch any drips.
11. Place the pie on the hot baking sheet and bake about 35 minutes. If the edges brown too fast, cover them with a foil ring. Bake another 10 minutes or so, until the crust is deep golden and the juices bubble thickly.
12. Cool the pie on a wire rack for several hours so the filling sets. Serve at room temperature with whipped cream or vanilla ice cream.