Preheat oven to 375 degrees Fahrenheit and spray a cookie sheet with cooking spray.

Place pastrami and sauerkraut in a bowl and add mustard and honey. Mix well to combine.

Lay pastry squares on a clean work surface or baking mat and put one teaspoon of pastrami mixture on one side of the square.

Fold in half into a rectangle and press shut with your fingers. Use a fork to crimp the edges and secure shut. Place on prepared cookie sheet. Continue with all the puff pastry squares.

Using a pastry brush, spread beaten egg on each pocket and bake in preheated oven for 15 minutes or until golden brown.

Serve hot or at room temp.