250-300g/9-10陆oz button mushrooms, cleaned
4 ripe tomatoes, cut in half
1 kg/2lb 3oz mashed potato
450g/1lb plain white flour
125驳/4陆辞锄 plain flour, plus extra for dusting
1 tsp bicarbonate of soda
salt and freshly ground black pepper
1 tsp cream of tartar
4 tbsp olive oil
1 tsp sea salt
salt, to taste
1 tsp sugar
2 tbsp butter, plus extra to serve
300ml/10陆fl oz buttermilk
8 free-range eggs
8 rashers smoked bacon
8 slices ready-made black pudding
8 beef or pork sausages