Make this simple supper of a wintry evening, sprinkling over a little grated cheese before cooking for good measure.
Preheat the oven to 200C/400F/Gas 6.
In a large non-stick casserole dish heat the dripping. Add the onion and cook for five minutes.
Meanwhile, in a large frying pan, heat a little olive oil and fry the mince, stirring, until browned all over. While the meat is frying, break up any lumps with the back of the spoon.
Stir the onions and add the flour (this helps to thicken the juices) and stir. Mix well and add the bay leaves, thyme and the anchovy essence and stir.
To the onion mix add the chopped tomatoes, stock (keep a little aside, for putting into the mince pan to de-glaze the pan) and Worcestershire sauce.
Add the cooked mince and then pour the stock mixture into empty mince pan, scraping off any bits of mince left in the pan. Pour the remaining stock into the pan containing the sauce mixture.
Bring the mixture to the boil, adding a pinch of salt and freshly ground black pepper and let it simmer for about 45 minutes.
For the mash, boil the potatoes, then drain them in a sieve and place into a clean bowl. Add the milk, butter and egg yolk, and mash together. Season with salt and freshly ground black pepper.
Pour the meat into an ovenproof dish and spread the mash on top, smooth over and mark with a spatula.
Put the dish into the oven and cook until the surface is bubbling and golden-brown.