Place chicken between two pieces of wax paper and flatten to an even thickness with a rolling pin.

Break an egg into a bowl and whisk to mix.

Add dry ingredients (flour, salt and pepper) into a bowl.

Melt butter in a large skillet.

Dip chicken in egg and coat in flour mixture. Add to hot butter in skillet and cook until slightly browned on both sides.

Add sliced mushrooms to skillet. Put on medium heat, cover and cook for 10 minutes.

Drain off excess butter. Add evaporated milk. Simmer over low heat 10 minutes.

Transfer chicken to warm platter.

Add champagne to liquid in skillet. Bring to a rapid boil and stir until liquid is reduced to a creamy consistency. Add milk if it becomes too thick.

Spoon over chicken and serve.