All the flavors of French Onion Soup are loaded into this French Onion Twice Baked Potato.
Wash each potato well, and prick holes all around the potato (carefully), using a knife or fork.
Using a sharp knife, slice the top off of each potato (horizontally). You will not be using this part of the potato.
Using a spoon, remove the center of each potato and place it into a large mixing bowl. Be very careful not to tear the potato skin of the hollowed out part of the potato. Lay the hollowed-out potato shells on a baking sheet.
Add butter, provolone, and 1/2 cup of the gruyere cheese to the large bowl and mash with the spooned out potato until well mixed.
Filled the hollowed-out potato skins with the cheese and potato filling.
Top each potato with the onion mixture and the other half of the gruyere cheese. Bake for 15-20 minutes, or until the cheese is melted.