Bring a large pot of salted water to a boil.

Trim the stems off the asparagus

Peel the white asparagus

Boil the asparagus for 10 minutes drain well and set aside.

Preheat oven to 375 degrees F

While the asparagus is cooking, roll out or pat the puff pastry sheets into an 8" x 12" rectangle.

Brush the sour cream on top and sprinkle with the thyme leaves.

Lay the asparagus on top and sprinkle the shredded Swiss cheese evenly over the top.

Place in the oven and bake for 20 minutes.

Remove, let cool for 10 minutes before slicing and serving.