Mix together the beef, potatoes, rutabaga, onion, flour, salt, and pepper in a bowl.
Add the flour, salt, cold butter, and cold lard to a food processor. Pulse a few times until the mix looks like breadcrumbs. Slowly add in the ice water. Pulse until incorporated.
Knead the dough on a floured surface. Cut into 4 equal pieces.
Roll a dough portion to an 1/8” thick.
Lay the rolled dough over the patty press. Scoop a cup’s worth of filling into the center. Add a tbsp of diced butter over the filling.
Fold over and crimp. Alternatively, if you don’t have a pasty press, take a plate and place over the rolled out dough. Using a knife, cut around the plate to get a circular piece of dough. Scoop the filling and butter in the center. Carefully fold one side of the dough to the other and crimp with a fork.
Lay the pasties on a baking sheet lined with parchment paper. Brush each pasty with the beaten egg wash.
Bake in a preheated 350° oven for 40-50 minutes until golden brown.
Ladle over a scoop of beef gravy for serving.