In a large bowl, whisk together the flour, salt, and sugar until well combined.
Add the chilled butter to the flour mixture. Using a pastry cutter or your fingers, mix until the mixture resembles coarse crumbs.
Gradually add the ice water, one tablespoon at a time, until the dough comes together. Be careful not to overmix.
Divide the dough into two discs, wrap each in plastic wrap, and refrigerate for at least 30 minutes.
Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
On a lightly floured surface, roll out one disc of dough to about 1/8 inch thick. Cut out rectangles (about 4x6 inches) using a knife or pizza cutter. Repeat with the second disc.
In a mixing bowl, combine the cream cheese, cooked sausage, cheddar cheese, chopped chives, and a pinch of black pepper. Mix until smooth.
Place a tablespoon of the filling on one half of each dough rectangle, leaving a border.
Fold the other half of the dough over the filling and press to seal the edges. Use a fork to crimp the edges for a decorative touch.
Brush the tops of the pop tarts with the beaten egg for a golden finish.
Make small slits on top of each pop tart to allow steam to escape.
Bake in the preheated oven for 20-25 minutes or until golden brown.
Let cool slightly before serving.
Notes
Serve warm on a rustic wooden board, garnished with extra chopped chives. Pair with scrambled eggs or fresh fruit.