50 g grated Parmigiano Reggiano
100 g butter
200 g flour
3 egg yolks
50 g sugar
Sift the flour into a bowl, add the softened butter, cut into small pieces, and a pinch of salt. Mix the ingredients until they form a solid dough, add the egg yolks, the grated Parmigiano Reggiano and a pinch of pepper. Knead the ingredients until they form a soft, smooth dough. Wrap the ball of dough in cling wrap and refrigerate for about 1 hour.
Roll the dough out to a thickness of about half a centimetre, then using a fluted pastry cutter, cut into strips of about 6 cm x 2 cm. Brush the strips of dough with the egg whites and sprinkle lightly with sugar. Arrange them on a parchment-lined baking sheet. Bake in a preheated 180°C oven for about 20 minutes. Allow to cool. Serve cold.