Make the Dough: In a large mixing bowl, combine flour and salt, create a well in the center. Cut in cold butter until mixture resembles coarse crumbs. Gradually add ice water, mixing until a soft dough forms. Shape into a ball, wrap in plastic wrap, and chill in the refrigerator for 30 minutes.

Prepare the Filling: Preheat your oven to 400°F (200°C). Dice beef into small pieces, chop potatoes, onion, and rutabaga. Combine all in a bowl with salt and pepper, mixing well.

Assemble the Pasties: Roll out dough to ¼ inch thick, cut large circles. Place filling on one half of each circle, add butter on top, fold and crimp edges to seal.

Bake: Transfer to lined baking sheet, brush tops with egg wash, bake for 40-50 minutes until golden brown. Rest for 10 minutes before serving.