1 cup freshly grated Parmesan cheese
1 cup freshly grated Gruyere cheese (optional)
2 sheets frozen puff pastry, thawed
Preheat oven to 375°F. Line two cookie sheets with parchment paper and set aside.
Sprinkle a good amount of Parmesan cheese on a silicone baking mat, wood or marble work surface. Lay one puff pastry sheet on the cheese surface, and with a rolling pin, roll it out a little bit to make it thinner. Sprinkle with Gruyere cheese and roll the surface, embedding the cheese. Sprinkle with Parmesan cheese again.
Using a pizza cutter or sharp knife, cut the dough into ½- to 1-inch strips.
Twist each strip and place on parchment lined cookie sheet, spaced about an inch apart.
Bake until the straws are golden brown, about 10 to 15 minutes.
Repeat the process for the second sheet. Depending on how thinly you slice the strips, each pastry sheet can yield 20 to 30 cheese straws.