2. Sift the flour, baking powder and mustard into a large bowl. Add the salt and butter, then use your fingertips to rub it into the dry ingredients. Stir in the chopped watercress and two thirds of the cheese and mix well.
3. Make a well in the centre of the dry ingredients, add the buttermilk and mix together with a round bladed knife to form a soft dough.
4. Very lightly knead on a floured surface, then use a floured rolling pin to roll the dough to a thickness of 2.5cm. Use a 6cm plain round cutter to press out circles of the dough, re-rolling lightly, as necessary. The mixture should make 9 scones.
5. Place the scones on a large oiled baking sheet. Brush each with a little buttermilk (or milk), top with a sprig of watercress, then scatter over the remaining cheese. Dust with a little pinch of cayenne pepper if liked, then bake in the centre of the oven for 20-25 minutes or until golden on top. Leave to cool on the baking tray for 5 minutes before serving warm.
Recipe courtesy of www.watercress.co.uk