In a large bowl, whisk together the flour and salt. Cut in the cold shortening with a pastry blender until the mixture resembles coarse crumbs. Gradually stir in cold water until a shaggy dough forms. Shape into a ball, wrap in plastic, and refrigerate for 30 minutes.

While the dough chills, combine ground beef, potatoes, rutabaga, carrots, and onion in a large bowl. Season generously with salt and pepper.

On a lightly floured surface, divide dough into six equal portions. Roll each into a 7-inch circle. Spoon about ⅓ cup of filling into the center of each circle.

Fold dough over filling to form a half-moon. Crimp edges tightly with a fork to prevent leaks.

Place pasties on a parchment-lined baking sheet. Brush tops with melted butter. Bake at 375°F (190°C) for 60–70 minutes or until golden brown and filling is tender.

Allow pasties to cool for 10 minutes before serving to let the juices settle.