Grease a 9" baking dish with butter (you can use an oval pan, a square pan, or a round pan. I used my 9"x9" square baking dish)
Slice all of the potatoes using a knife or mandolin so that they’re about ⅛” thick
Arrange the sliced potatoes in your greased dish in a spiral formation. In a small bowl, mix together the potato spices. Evenly distribute the mix of salt, pepper, and smoked paprika on top of the potatoes
Preheat your oven to 375℉
In a small microwave-safe bowl, combine the milk and heavy cream and warm them for 45 seconds in the microwave. Set that aside
In a saucepan over medium heat on the stove, melt the butter for the béchamel sauce
Once the butter is melted, whisk in the flour and continue whisking it for about 1 minute until the flour has dissolved and you’re left with a silky smooth roux
Very slowly pour the warm milk and heavy cream into the saucepan while continuously stirring (you don’t want this to burn, otherwise, you will have to start over!)
Add the spices to the béchamel sauce while whisking and continue whisking over medium heat for ~5 minutes until it thickens
Evenly pour the béchamel sauce over the potatoes (it will seem like a lot, but trust me, it will bake perfectly!)
Cover the dish with foil and bake at 375℉ for 45-50 minutes
Remove the foil and continue baking until the tops of the potatoes are perfectly golden and crispy (25-30 minutes). If you’d like to set the oven to broil during the last 2-3 minutes for an extra crisp on top, go for it! Just make sure to keep a very close eye on it.
Top with chopped parsley (optional but delicious) and enjoy!
