Put the currants into a heatproof bowl and cover them with freshly boiled water. Set aside to soften.
Begin by rubbing the butter into the flour in a medium-sized bowl.
Add the salt, sugar and dried yeast and stir briefly. Pour in 200ml of the lukewarm milk and mix into a dough. Add more milk, little by little, as required to incorporate all of the flour into the dough.
Tip the dough onto a lightly floured worktop and knead for 10 minutes.
Place in a large bowl (clean), cover with a clean tea towel and leave to rise for 2-3 hours until doubled in size.
When the dough is ready drain the currants from the water and lay on kitchen paper. Blot them dry to remove excess liquid.
Knock the dough back and spread it out on a worktop. Sprinkle ⅓ of the currants over it, gather the dough up into a ball and knead for 2 minutes to distribute the currants evenly in the dough.
Divide the dough into 2 equal portions.
Roll one portion out to form a rectangle approximately 15cm wide and 22cm long.
Trim up to 1cm from each end to neaten the rectangle and scatter half of the remaining currants over the dough. Roll it up (to end up with a 20cm long log).
Use a large sharp knife to cut the log into 6 pieces.
Repeat with the remaining piece of dough and currants.
Lay the 12 cut buns onto a baking sheet lined with baking parchment (or use 2 baking sheets if you prefer them not to touch as they bake, making it necessary to pull them apart)
Cover the buns with a tea towel and leave to prove for 30-45 minutes until well risen.
Meanwhile, preheat the oven to 220C/ 425F/ GM 7.
Brush each bun with milk and bake for 10-12 minutes until golden brown and cooked throughout (if you have a probe food thermometer you can check the internal temperature is at least 95C/ 203F).
Slide onto a wire rack and allow to cool.
Optional: if making glazed currant buns let them cool completely then make the glace icing by mixing the icing sugar with a few drops of water to attain a slightly runny consistency that can be drizzled using a knife or teaspoon. Drizzle a little over each bun.