Heat the oven to 400 F (200 C/Gas Mark 6).
Place the mashed potatoes in a large bowl and add all the other ingredients to form a sticky dough. Add in herbs and gently combine.
Roll out the dough on a floured surface to approximately 1/2-inch thickness.
Cut into saucer-sized rounds then score a cross into the dough to mark 4 equal wedges.
Grease a baking sheet with butter and bake the scones for 20 minutes until golden brown and risen.
The scones can also be cooked on the stovetop on a griddle or heavy-based frying pan. Cook the scones 5 minutes on either side until golden and risen.
Servings 6
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.
Mashed potatoes made from starchy potatoes work best. The waxy varieties will create either a waxy or a lumpy mash. Traditionally, these work best with either Maris Piper, or King Edward potatoes, which are not typically available in the U.S.; try russet potatoes or Idaho potatoes. Always check that the variety you buy is suitable for mashing.
Ensure that the mashed potatoes are not too wet; don't add too much cream, milk, or butter. Drier mashed potatoes create a dough that will roll out more easily, especially if you include the egg.
If the dough is not firm enough, add a little more flour.