Begin by placing your pre-made pie crust into a 9-inch pie dish, gently pressing it into the edges for a snug fit. Refrigerate the crust to keep it firm.

Preheat your oven to 375°F (190°C).

In a medium bowl, combine cold, cubed butter, sugar, flour, cinnamon, and a pinch of salt. Mix until the ingredients resemble coarse crumbs. Set aside.

In a large mixing bowl, gently toss together the rhubarb, strawberries, sugar, cornstarch, orange juice, lemon juice, and a pinch of salt until well combined.

Pour the prepared filling into the chilled pie crust. Dot the top with small pieces of butter, then sprinkle the crumb topping evenly over the filling.

Place the pie on a baking sheet and transfer it to the oven. Bake for 60-80 minutes, checking at the 60-minute mark.

Once baked, remove the pie from the oven and let it cool at room temperature for 2-3 hours.