it’s simple. I had the butcher slice the filet as thin as he could.
I only put sautéed onions, salt, and pepper. I cook the onions first in a bit of olive oil for about five to 6 minutes.
Add salt and pepper to taste. Remove for the pan.
Then I cook the steak salt and pepper and return the onions to the meat. I get really good bread at the bakery.
Put mayo (duke’s) on both sides. Add the onion and beef mixture.
Add shredded mozzarella or provolone.
Bake in a 375 oven until mozzarella melts. Add the fresh parsley for color.