Preheat the oven to 375F and line a large baking sheet with parchment paper.
Unroll the defrosted puff pastry sheet onto a lightly floured surface (like a cutting board) horizontally, it should be about 12-14 inches wide by 10 inches tall (roll out into this shape if needed).
Make the egg wash by whisking together 1 egg with 1 tablespoon of water. Then, lightly brush the entire sheet of puff pastry with the egg wash. Set the egg wash aside.
Sprinkle the entire surface of the puff pastry sheet with the freshly grated gruyere cheese and dried thyme.
Layer the prosciutto slices side-by-side on top of the grated cheese, slightly overlapping the slices. Lightly press the cheese and prosciutto into the puff pastry (you can also use a rolling pin to roll over and press in the cheese gently).
Use a pizza cutter or sharp knife to cut the puff pastry into 1 inch thick strips, you'll get about 11-12 cheese twists. Note: If you prefer 22-24 cheese twists, cut the strips in half.
Grab both ends of one strip and gently twist in opposite directions to create a spiral - place on the baking sheet and repeat until you've created puff pastry twists with all of the dough, making sure to leave space between the twists on the prepared baking sheet.
Place in the fridge for 10 minutes - this helps the puff pastry cook better in the oven. After 10 minutes, remove the baking sheet from the fridge and using a pastry brush, brush each puff pastry cheese twist with egg wash.
Bake for 18-20 minutes in the 375-degree oven or until the cheese twists are puffed and starting to turn golden brown on the bottom. Gently flip each cheese twist and then place back in the oven to bake for 3 more minutes.
Remove from the oven and let the cheese twists cool completely on the baking sheet.
Before serving, drizzle with some hot honey OR serve with a side of hot honey or dijon mustard for dipping.
Best enjoyed the day they are made - you can definitely make these ahead of time! (See below for make-ahead freezer option)