Preheat your oven to 180 C (350 F). Grease a 8x8 baking dish with butter.
Thee potatoes sliced with a mandolin.
Onion diced, cheese shredded (I use blocks and shred myself), bacon cooked and chopped, and the flour.
Mix together the onion, cheese, bacon, flour, then season as desired with salt and pepper.
Spread 1/3 of the potatoes on the bottom of the baking dish, then spread 1/3 of the cheese mixture over the potatoes. Repeat the layers two more times, cheese mixture will be last.
Mix together the cream and milk and pour over the top of the casserole.
Cover with foil and bake for 45 minutes. Remove the foil and bake for another 25 to 30 minutes or until the potatoes are tender.
Remove from oven, let rest for a few minutes, serve.