Put beef, onion, mushrooms, stock, Worcestershire sauce, salt and pepper in slow cooker

Cook on low for 5 hours or until meat is tender.

Take lid off slow cooker and turn on high

Add the corn flour or gravox to the slow cooker and stir.

Leave cooking on high until sauce thickens, remove some liquid if necessary.

Cool pie filling.

Grease pie tin and line with pasty

Add chilled pie filling to pastry crust.

Top pie with pastry and crimp edges.

Brush pastry with egg wash and bake till golden.