Preheat oven to 400F and line a couple cookie sheets with parchment paper
In a large skillet or dutch oven, heat olive oil over medium high heat.
Remove sausage from casings and cook, stirring often and breaking sausage into small crumbles.
Meanwhile, wash kale, remove large stems and coarsely chop.
Once sausage is cooked, add in kale and cook until just wilted.
Flour work surface and roll out one sheet of puff pastry to about 15 inches square.
Using a knife or pizza cutter cut the sheet into 9 squares.
In a small bowl, whisk together the egg and milk to make an egg wash.
Add cheeses to sausage mixture and season with salt and pepper to taste.
Take one of the squares and paint the edges with the egg wash.
Place about a quarter cup of filling in the square and top with a second piece of puff pastry.
Crimp the edges with a fork and make a few slits in the top with a knife.
Repeat with the remaining filling and pastry. It should make about 18 pockets.
Place the pockets on prepared baking sheet, cover with egg wash and sprinkle with salt.
Bake for 15-20 minutes until golden brown.
Notes
For make-ahead meals, freeze pockets in an airtight container, being careful to place wax paper or parchment between pockets so they don't stick together. Just before baking, paint with egg wash, or if just making one, a little oil or butter will do the trick. Bake at 350F from frozen for about 25 minutes.