Preheat oven to 375°F (190°C). 

In a large bowl, whisk together flour, walnuts, sugar, baking powder, salt, thyme and pepper. 

Using a coarse cheese grater, grate frozen butter directly into dry ingredients, stirring occasionally to prevent butter from sticking together. 

Pour milk into the mixture and stir gently with a wooden spoon until mixture just comes together to form dough.  Turn the dough over a few times to gather up any remaining bits of flour.  Dough should not be sticky. If it is, add a bit more flour. 

Transfer the dough to a floured cutting board and divide into 4 equal pieces.  Working quickly, using your hands, shape each piece into a round, flat disk, about 3/4-inch (1.9 cm) thick.  Cut each disk into 8 even-sized wedges.  Arrange on a parchment-lined baking sheet. Brush tops with milk.  Sprinkle with finely chopped walnuts. 

Bake for 12 minutes, or until golden brown.  Transfer to a wire rack and cool slightly.  Gently pull tops off the scones or cut horizontally.  Fill with desired fillings or top half with desired toppings.
 
Filling/Topping Suggestions: