Au gratin potato recipe. A classic.
Preheat oven to 350˚F
Boil potatoes until just tender, 20-25 minutes; drain.
When cool enough to handle, peel and slice the potatoes into 1/4" rounds.
Layer the potato slices into a 3 quart baking dish.
In a large saucepan, melt butter over medium heat.Add flour, stir while cooking, 1-2 minutes.
Whisk in milk and add garlic. Season with salt and cayenne pepper.
Stir in cheddar cheese and all but 2 tablespoons of parmesan cheese.
Pour over the potatoes and use a spatula to evenly distribute and stir slightly into all the layers.
Sprinkle remaining parmesan cheese over the top.
Tent with tinfoil or put a cover to prevent the cheese from burning.
Bake for 30 minute or until the potatoes are tender and the dish is bubbling . Remove the tent or lid for the last 5 minutes to the cheese becomes nicely browned.
Let stand for 5 minutes before serving.