300²µ/10½´Ç³ú chestnut mushrooms, trimmed
2 red onions, thinly sliced
2 tbsp thyme leaves
100²µ/3½´Ç³ú plain flour
salt and pepper
2 tsp soft brown sugar
pinch of salt
1 tsp sesame seeds
1 tbsp sherry vinegar
100²µ/3½´Ç³ú strong white bread flour
1 tbsp sunflower oil
165g/5¾oz chilled unsalted butter
25g/1oz unsalted butter
1 free-range egg, lightly beaten, to glaze
100²µ/3½´Ç³ú black pudding, cut into 1–2cm/½-¾in pieces
300²µ/10½´Ç³ú top-quality sausagemeat (or skinned butcher’s sausages)