Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Sauté mushrooms in olive oil and season with salt.

Roll out the puff pastry and cut the outer thirds into diagonal strips.

Arrange half the cheese down

the center of the puff pastry,

followed by the mushrooms, then

by the basil, then by the rest of

the cheese. Cross the strips over

the filling, alternating sides, to

close the braid.

Combine the egg and cream and brush over the pastry.

Bake for 40 minutes, or until golden brown.