Preheat your oven to 425°F (220°C). Roll out the pie crust and fit it into a 9-inch pie dish. Set aside.
In a large mixing bowl, combine cranberries, sliced apples, sugar, cornstarch, cinnamon, nutmeg, salt, and lemon juice. Toss gently to coat evenly.
Pour the fruit filling into the prepared pie crust, spreading it out evenly.
Cover with the top crust or create a lattice pattern. Trim excess crust and crimp edges to seal.
Cut a few small slits in the top crust to allow steam to escape. Optional: brush with a little milk or beaten egg for a golden finish.
Bake in the preheated oven for 45-50 minutes, or until the crust is golden brown and the filling is bubbling.
Remove from oven and allow to cool for at least 2 hours before serving. Enjoy warm or at room temperature!