Sprinkle the chicken breasts with salt, pepper, garlic powder, and onion powder, tossing to coat evenly.
2. Step
On a cutting board, place a chicken breast between two sheets of plastic wrap and pound until about ½-inch (1 cm) thick with a meat mallet, rolling pin, or heavy pan.
3. Step
Remove the plastic wrap and place a layer of Swiss cheese, then ham, then one more layer of Swiss cheese.
4. Step
Evenly roll the chicken, and place onto a new sheet of plastic wrap.
5. Step
Wrap the chicken in the plastic wrap, twist the excess plastic, and roll the chicken while twisting the sides in to tighten and firm up the roll of chicken cordon bleu. Tie the excess and chill in the fridge to set for 30 minutes.
6. Step
Preheat oven to 400°F (200°C).
7. Step
Cut the puff pastry sheets in half and gently roll out width-wise.
8. Step
Brush the pastry with mustard and place the chicken on to the bottom edge of the pastry.
9. Step
Tightly roll the chicken in the puff pastry, pinching the seams together to close and folding the sides under the bottom.
10. Step
Place the chickens rolls on a greased baking sheet and brush all sides with egg wash.
11. Step
With a fork, score a decorative design onto the surface of the puff pastry.
12. Step
Sprinkle with salt.
13. Step
Bake for 35-40 minutes or until the puff pastry is a dark golden brown and the internal temperature of the chicken is 165°F (75°C).
