Preheat oven to 375 degrees Fahrenheit and line a baking sheet with parchment paper.

In a large mixing bowl, combine self-rising flour, unflavored whey protein, and salt.

Add Greek yogurt to the dry ingredients and mix until a dough ball forms, adding minimal flour if too sticky.

Turn dough onto a floured surface and knead for 2 minutes until smooth.

Roll the dough out into a large rectangle approximately 1/4 inch thick.

Cut the dough into 12 equal-sized rectangles of approximately 3x5 inches.

In a small bowl, combine scrambled egg whites, turkey sausage, cheese, and pepper.

Distribute the filling evenly onto 6 of the rectangles, leaving a 1/2 inch border.

Place the remaining 6 rectangles over the filling and crimp the edges with a fork to seal.

Poke 3-4 holes in the top of each pastry with a fork to allow steam to escape.

Brush the tops with a beaten egg wash and bake for 18 to 20 minutes until golden brown.

Transfer to a wire rack and allow to cool for 5 minutes before serving.