Shred Gruyere cheese
Mince garlic and shallots and thyme leaves. Then sauté in butter. Add milk, cream, salt and pepper.
Slice potatoes and add to the pot. Simmer for 1 min. Layer the potatoes, cheese and sauce in pan.
Cover with parchment and foil. Bake at 375 F for 45-60 min, uncover and broil 5-10 min. Cool 30 min.