beef tenderloin (chateaubriand) - 4-4.5 pounds (about 4-4.5 pounds)
salt - to taste (to taste)
pepper - to taste (to taste)
Dijon mustard - as needed (for brushing)
clarified butter - as needed (for searing)
mushrooms - 10 ounces (finely chopped, portobello or your choice)
shallots - as needed (finely chopped)
butter - as needed (for cooking mushrooms)
prosciutto - as needed
ham - as needed (black forest, optional)
tarragon - as needed (fresh, or thyme/rosemary)
egg white - 1 (for binding duxelles)
flour - 1 cup (for crepes)
eggs - 2 (for crepes)
milk - 1 cup (for crepes)
puff pastry - as needed
egg yolks - as needed (for egg wash)
milk - as needed (for egg wash, optional)
fleur de sel - as needed (for finishing)