In a large bowl or the bowl of a stand mixer fitted with a kneading hook, stir together the flour, salt, yeast and sugar. Warm the butter and milk in a small saucepan until the butter has melted. Let the milk cool slightly, until it is just about cool enough to dip your finger in (about 120F).
Pour the milk/butter mixture into the flour and knead to form a soft and just slightly sticky dough. You may need to add additional flour.
Remove dough to a greased bowl and cover with plastic wrap to rise until doubled, about 1 hour.
Turn the dough onto a floured board and cut into 8 equal-sized pieces. Roll each one into a ball, placing them on a parchment lined baking sheet as you go.
Set the oven at 390F. Dust the buns lightly with flour and cover with a tea towel. let rise for 10-15 minutes more.
Bake for 18-20 minutes until they are pale golden on top and sound slightly hollow when tapped on the bottom.
Remove the buns from the baking sheet to a cool slightly. Enjoy warm (traditionally served warm) or fully cooled.
To serve make a cut in each bun from about 1/3 down in the front, angling back and down, to about 2/3 down the back, without cutting all the way through. Butter the bottom, then spoon a good dollop of jam inside. Spoon or pipe whipped cream on top. Dust with icing sugar to serve.