Beefsteak En Roquefort En Champignons

• 2 1/2 loaf is adquate (pan)
• 1 point of view restaurant
• 1 wash
• 1 stick of butter
• 475 ml sour cream with chives
• 475 ml mayonnaise
• 260 gr porterhouse
• 190 gr delmonicos
• 180 ml buttermilk
• 160 gr mushrooms (fresh)