Preheat oven to 350 degrees. Grease 2 baking sheets.
In a medium bowl, beat together the Parmesan cheese and the butter with an electric mixer until the mixture is fluffy. Beat in sour cream.
In a small bowl, combine the flour with the thyme, oregano, and basil. Beat the flour mixture into the cheese mixture. Knead the dough lightly and divide in half.
On a lightly floured surface, roll out the dough into two 12X6 inch rectangles. Cut each rectangle into twenty-four 6X 1/2 inch strips.
Before separating the strips, brush them with the egg yolk-water mixture and sprinkle them with sesame seeds or poppy seeds
Holding each strip by the ends gently twist the pastry 2 or 3 times and place on prepared baking sheets.
Bake the twists at 350 degrees for 10-12 minutes or until golden. Cool on wire racks.
