In a food processor, combine flour and salt, pulsing until blended. Add butter and lard, processing until it resembles coarse crumbs. Gradually add cold water, pulsing until the dough comes together. Chill for at least 3 hours.

Preheat your oven to 350°F (175°C). Divide the chilled pastry dough into 6 pieces and roll each into a log shape. Flatten each into an 8-inch circle.

Layer the filling on one half of each rolled-out dough starting with potatoes, rutabaga, onion, and cubed beef. Season and add butter and flour.

Moisten the edges of the pastry circles with water. Fold the dough over, sealing the edges by crimping.

Transfer each pasty onto a baking sheet lined with parchment. Cut slits in the tops for steam to escape.

Brush the tops with beaten egg and bake for 40-50 minutes or until golden brown.

Remove from oven and let cool on a wire rack for 10 minutes before serving.