Brown the beef in beef fat and set to one side get a good caramelisation on the outside
Diced the veg and use the same pan to fry in beef fat when softened add the thyme, rosemary, garlic and tomato paste season with salt.
Add the beef back in then add the wine, Worcestershire sauce and mustard reduce by half then add the stock. simmer this for 1 hour or until it's reduced sufficiently (If your stock doesn't thicken naturally you can use a little cornstarch mixed with water)
Bake the potatoes for 60 mins at 180c pass through a drum sieve or just mash the flesh while it's still hot
Beat through cold butter then add the milk, add an egg yolk, season to taste
Add the meat mixture to an oven proof dish top with the mash, more butter and cheddar cheese
Bake at 180c for 40-45 mins
