1. Preheat oven to 400 degrees F. Sift flour, salt and spices into a bowl. Cut in butter finely until mixture resembles bread crumbs. Add grated cheese and mix well.
2. Mix egg with cold water. Add 2 tablespoons of egg mixture to cheese mixture and mix to form a fairly stiff dough. Knead gently on a lightly floured surface.
3. Roll out dough to a 12 x 6-inch rectangle. Trim edges. Cut in half lengthwise and transfer to a baking sheet. Brush each half with remaining egg mixture. Sprinkle one half with sesame seeds and the other half with poppy seeds. Cut each half in 10 triangles and separate slightly to prevent sticking.
4. Bake in preheated oven 10 to 12 minutes or until light golden and cooked through. Cool on a wire rack. Store in an airtight container up to 2 weeks.