Cut a small pocket in each breast lengthwise through the center of the breast. Pound the chicken lightly, then season with salt and pepper.
Dust the outside of the chicken with a little flour and saute them until they are just barely cooked. Let them cool. Stuff the center with cooled Duxelle.
Roll out puff pastry patty into 8 circles and place them onto a floured baking sheet. Place chicken breast on each circle, and brush the edges of each circle with egg wash. Roll out the rest of the dough and cut 8 more circles, which should be a little thicker than the circles under the chicken. Place a circle on top of each breast, and press the pastry edges together firmly, to form a seal. Paint the top crusts with egg wash.
Chicken can be prepared up to this point early in the day, and then refrigerated until baking time. Just make sure that the chicken is dry before enclosing it in the crust, so that the bottom crust will remain crisp.
Before serving, bake at 400 degrees until the crust is puffed and brown, about 30 minutes. Serve with Sauce Supreme on the side. Serves 8.
