Preheat the oven to 200C/400F/Gas 6.
Pour the Worcestershire sauce into a pan and place over a medium heat. Bring to the boil, then reduce the heat and simmer until reduced by just over a third of its original volume.
Place the tomatoes onto a baking tray and dot with 25g/1oz of the butter, and season well with salt and freshly ground black pepper. Transfer to the oven to cook for 20-25 minutes.
Place the bacon onto a clean baking sheet and place in the oven for 5-6 minutes, or until crisp and golden-brown.
Heat a frying pan until hot, add 25g/1oz of the butter and the mushrooms and fry for 2-3 minutes. Season well with salt and freshly ground black pepper.
Place the warm mashed potato into a bowl and mix with the remaining butter and the flour to form a soft dough. Season with the ground mace and salt and freshly ground black pepper.
Roll out the potato dough to 1.5cm/½in thick. Cut out rectangles approx 9.5cm/4in by 6cm/2in wide.
Heat a griddle pan until very hot. Brush the griddle very lightly with oil and add the potato scones. Cook for about 20-30 seconds on each side, or until golden brown and crisp all over.
Crack the eggs into a small frying pan and cook over a gentle heat trying to avoid crisp egg white. Cook to your preference.
To serve, place a tattie scone into the centre of each warmed plate, then place some of the mushrooms on top.
Place the cooked tomatoes into the same pan as the Worcestershire sauce so that they soak up the flavour, then place them on top of each pile of the mushrooms.
Place a rasher of cooked, crisp bacon on top, then add a fried egg on top of that.
Place a second tattie scone on top to form a lid. Pour any excess Worcestershire sauce reduction around the plate and serve.
