Preheat oven to 350 degrees. Coat baking sheet with nonstick cooking spray, set aside.
In a medium saucepan, melt butter. Add the onions and saute over medium heat for 3 minutes.
Add beer, stir for an additional 3 minutes.  Pour onion mixture into a large bowl. Add chicken, bacon, mustard, salt and pepper. Combine thoroughly.
Cut or tear bread dough into 6 equal pieces and roll into balls. Press and pull each ball into a thin, flat circle.
Top each circle with equal amounts of chicken mixture, then equal amounts of cheese.
Pull edges together and press to seal. Brush each calzone with egg white.
Place calzones on baking sheet and bake for 20 minutes or until golden.