Roast the garlic at 375F for 1 hour or until golden. Let it cool.
Blend the garlic with the milk.
Add the cream, milk, salt, white pepper, allspice, paprika and herbs de provence. Warm up.
Using a mandoline, thinly slice the potatoes.
Rub butter on a baking dish (8x8) and place 2 sheets of parchment paper overlapping each other.
Add a ladleful of the cream, arrange a layer of potatoes, more cream and more potatoes. Add a thin layer of cheese followed by a layer of potatoes, cream, potatoes, more cheese, potatoes, cream, potatoes, cream, cheese, potatoes, cream, potatoes and cream. A total of 8 layers of potatoes.
Cover with foil. Bake at 350F for 75 minutes.
Let cool. Place parchment paper over the potatoes, a baking sheet on top and heavy cans. Refrigerate for 8 hours minimum or overnight.
Slice off the edges. Cut into stacks.
Place on a baking sheet lined with parchment paper, top with the remaining gruyere and parmigiano reggiano.
Bake at 425F for 35-45 minutes until deeply golden.
Top with chives, creme fraiche and caviar.
