Cut the butter into small cubes and blend them in the blender/mixer or food processor.
Then add the cheese, flour, salt, pepper powder, red chilly powder and blend again.Then add the egg yolk, and mix. Slowly add the water to form a dough .
Roll the dough using some flour to dust, cut into small cookies.
Sprinkle some oregano or grated cheese on top and bake them at 180℃ , in a preheated oven for just 10 minutes.
P.S : for the eggless version, instead of the egg yolk, use 3 tbsp of thick buttermilk and also add 1/4th tsp of baking powder.