In a pot, place rhubarb slices, coat them with sugar, cover and let stand for 8 H if not overnight. Juice will appear.
Being rhubarb to boil til soften, along with the juice and citric acid. Once softened, stir in cornstarch solution (diluted cornstarch in water).
Take off from heat, let filling cool to room temperature.
Meanwhile, mix salt, flour, and butter until coarse texture, then add in icy water. Knead until dough formed. Flattened into a disk, wrap, and chill for an H.
Divide into 2, roll each as top and bottom crust.
Lay 1 skin on pie plate, pour filling in center, then top with the other skin, and poke holes
Bake pie on preheated 450 F for 15 mins, reduce heat to 375 F and bake for another 35-40 mins
Enjoy!