Serve these at your next party for an elegant side dish. Guests will be impressed and they'll love the combination of crunchy tops and soft potatoes inside, all nestled in a puff pastry shell.
Defrost puff pastry according to directions on the package. Use only one sheet at a time, keeping the other one refrigerated. In general, defrosting at room temperature for about 40 minutes works.
Preheat oven to 375 degrees F. Spray or lightly oil by hand a 12-muffin tin. Set aside.
Either microwave the potato slices (covered in a microwave safe bowl) or boil them until they are pliable (slightly bendable), but not fully cooked. Once they are done cooking, put them in a bowl of cool water until needed.
The puff pastry sheet starts out about 9 1/2 -inches square. Roll it out to a rectangle about 10-inches wide by 14-inches long. Cut the rectangle into 6 strips, each slightly less than 2-inches wide.
Pull one strip of dough off of the rectangle. Roll it a bit more, so that it is about 2 1/2-inches wide. Brush the strip with the oil/butter. Sprinkle herbs, cheese, salt, and pepper along the top half of the strip.
Add potato slices, alternating Yukon gold and sweet potatoes, and leaving about 1-inch at the beginning and end of the strip.
Fold the bottom half of the pastry strip up to the middle of the potato slices and dab a bit of oil/butter at each end of the strip. Roll the strip gently but firmly, taking care not to pull it too tight.
When the rose is completely rolled, place it in the first muffin cup and repeat with the next 11 strips of dough and the rest of the potato slices.
Bake the roses for about 45 minutes, until the edges of the potato slices peeking out are browning and the pastry shell is golden. If the potato slices darken before the pastry shell is cooked, gently put a piece of aluminum foil over the roses and let them continue to bake. Once done, let them sit in pan for a few minutes before lifting them out.
How long it takes to microwave or boil the potato slices depends on a number of factors. Do not overcrowd the bowl or pot used to microwave or boil them in. In general, sweet potato slices take longer than Yukon golds so you might want to cook them separately.
It's easiest to cut the dough into strips with a pizza cutter. If you don't have one, use a sharp knife, with a ruler if you are concerned that you can't easily cut a straight line.
Although they are best eaten warm, you can reheat the roses at 375 degrees F in a regular or toaster oven.