In blender, blend mushrooms and chicken broth; set aside.
In skillet over medium heat, melt butter and mix in flour. Slowly add mushroom broth while stirring. It should start to thicken; if it doesn’t, add 1 tablespoon flour and stir well.
Add garlic powder and salt and pepper, to taste. Mix in heavy cream while continuing to stir. Remove from heat and set aside. Reserve until ready to cook and keep refrigerated, if necessary.
To prepare chicken:
Butterfly chicken breasts, making four thinner pieces.
In shallow dish, mix flour and lemon pepper seasoning. Coat chicken in flour mixture.
Melt butter over medium heat and add chicken broth. Pan fry coated chicken breasts then remove from pan and set aside.
Use champagne to deglaze frying pan and add mushroom sauce to heated champagne. Place chicken breasts back in pan in mushroom sauce and cook over medium heat about 5 minutes. Serve over rice.
Notes
Substitutions: Mushroom soup can be used in place of homemade mushroom sauce. Chicken broth can be used in place of champagne.