Heat a pan and melt-in 1/4 cup butter.
Put-in mushrooms. Cook for 3 to 4 minutes.
Put-in chicken, salt, ground black pepper, and sherry. Cook for 3 to 5 minutes.
Meanwhile, heat a sauce pan and melt the remaining 1/4 cup butter.
Add flour and stir until the mixture forms. Pour-in chicken broth and stir until the butter and flour mixture dissolve. Let boil.
Transfer the chicken broth mixture to the pan where the chicken is cooking.
Pour-in the heavy cream. Add thyme, pimento, parsley, and green peas.Let boil and cook until the sauce thickens.
Arrange puff pastry on a serving plate and top with chicken a la king.
Serve. Share and enjoy!