Preheat oven to 400 degrees F° Spray a 9x13 inch baking dish with cooking spray.
Slice potatoes 1/4 inch thickness. (I use my mandolin slicer)
In a separate bowl, whisk together cream, milk, flour, minced garlic, salt, and a little black pepper.
Place 1/3 of the potatoes in the bottom of the baking dish. Pour 1/3 of the cream mixture over the potatoes.
Repeat this two more times, ending with the cream mixture. Cover with foil and bake for 30 minutes. Remove foil and bake for 20 minutes, or until potatoes are golden brown and really bubbling. Add grated cheese to the top of the potatoes and bake for 3 to 5 more minutes, until cheese is melted and bubbly.
Remove from oven and let stand 10 minutes before serving.