The cheese in this crust and the lump of garlic butter that melts onto the centre makes this into something very special. The Worcestershire sauce is also a great help. I have no shares in the company, but ensure you always have a bottle in your cupboard as it gives a welcome lift to many otherwise pedestrian dishes
Heat the oil in a saucepan. Add the garlic and onion and fry until soft and slightly brown.
Increase the heat, add the minced beef and thyme leaves and fry until the beef changes colour.
Add the wine, half the stock, the Worcestershire sauce and the tomato puree. Simmer for 10 minutes.
Meanwhile, boil the potatoes in their jackets, then peel them. Add boiling milk and mash the potatoes while they are still hot. Season with salt and freshly ground pepper and add a blob of butter and the chives, if using.
Preheat the oven to 180°C (350°F/Gas 4).
Bring the remainder of the stock to the boil and thicken it well with roux. Stir it into the mince - it should be thick but still juicy. Taste and correct the seasoning.
Put the meat mixture into one large or six individual pie dishes. Pipe or spread the mashed potato over the top.
Sprinkle with the grated cheeses. Bake for 30 minutes, until the top is golden and slightly crispy. Serve with garlic butter and a green salad.