Dessert

Pulse the flour, salt, and sugar in a food processor until combined
Add the butter and process until the mixture resembles a coarse meal
Pour water in a slow steady stream through the feed tube until the dough holds together
Turn the dough onto the work surface, gather into a ball, divide in half, flatten into disks, wrap, and refrigerate for about one hour
Roll one portion of chilled dough into a 12 inch circle, fold, transfer to a 9 inch pie pan, trim to a 1/2 inch overhang, and refrigerate covered
Roll the second portion into a 13 inch circle, cut into 3/4 inch strips, place on a parchment-lined sheet, cover, and refrigerate for about 10 minutes
Place the sliced strawberries and rhubarb in a large bowl
Mix the cornstarch, sugar, and cinnamon in a small bowl
Sprinkle about 2 tablespoons of the prepared sugar-cornstarch-cinnamon mixture over the bottom of the chilled pastry crust
Add the remaining sugar-cornstarch-cinnamon mixture to the strawberries and rhubarb and gently toss to combine
Pour the fruit mixture into the prepared pie shell
Sprinkle the fruit with lemon juice and dot with unsalted butter
Lay half the pastry strips across the filling, weave the remaining strips into a lattice, trim to leave a 1 inch overhang, fold under the bottom crust, and flute the edges
Brush the lattice with milk and sprinkle with a little sugar
Refrigerate the assembled pie while you preheat the oven to 400°F and place a foil-lined baking sheet on the lower third rack.
Place the pie on the hot baking sheet and bake about 35 minutes, cover edges with foil if browning, and continue baking about 10 more minutes until crust is golden and juices bubble
Remove the pie from the oven and cool on a wire rack for several hours
Serve at room temperature