This is one of those effortlessly delicious and good-looking dishes that's great to have in your repertoire. It also re-heats really well, so bake it a day in advance if you'd like, then put in the oven to heat through just before serving.
|1 lb||puff pastry (thawed if frozen, according to package directions)|
|2 lb||potatoes (peeled and thinly sliced to 3/8-inch)|
|1 c||sour cream|
|1 t||rosemary (fresh, chopped)|
|1⁄2 t||garlic (minced)|
|1||egg yolk (beaten)|
Preheat oven to 350˚F.
Roll out the pound of puff pastry on a sheet of parchment paper. The separate sheeets will stick together as you roll. Roll it out into a 16x16-inch square. Transfer the parchment (with the pastry) to a large baking sheet. Cover and place in the refrigerator.
Place the peeled potatoes in a large mixing bowl. Fold in the sour cream, and sprinkle with salt, rosemary, minced garlic, and a generous pinch of black pepper.
Remove puff pastry for the refrigerator, then arrange the potato and sour cream mixture in a long rectangular mound in the center of the puff pastry square. Fold the sides over to cover the potatoes, and gently press down the ends to seal. Run a very sharp knife crosswise over the strudel, creating several shallow diagonal slashes.
In a small bowl, combine the egg yolk and the milk. Brush this over the top of the strudel and sprinkle with a bit of salt. Bake for 45 minutes. occasionally rotating the pan to ensure even browning. Serve hot.