Melt butter in a pan, add diced leeks and carrots then cook until soft (about 15 mins)
Pour in heavy cream, sprinkle in seasonings then let mixture simmer for a couple minutes
Remove from heat, add in cheese then set aside to cool
Roll out puff pastry on floured surface then sprinkle seasoning on the dough
Set the salmon on the dough, spread vegetable mix on top of the salmon, fold over the puff pastry, pinch the corner then brush the the pastry in egg wash
Flip the salmon over, place it on baking sheet with parchment paper, lightly score the dough then add more egg wash
Bake for 25 to 30 minutes at 375 degrees
