Heat oil in large pot over medium heat.
Season beef cubes with salt and pepper thoroughly.
Brown beef on all sides until golden.
Remove beef and set aside on plate.
Add onions to same pot and cook.
Stir in carrots and cook until softened.
Sprinkle flour over vegetables and stir well.
Pour Guinness slowly while stirring mixture constantly.
Add beef stock and tomato paste gradually.
Return beef to pot with bay leaves.
Simmer covered for 1.5 hours until tender.
Transfer filling to pie dish and cool.
Cover with pastry and brush with egg.
Bake at 400°F for 25 minutes.