Source  Mel's Kitchen Cafe

Recipe Added:  11/5/2011 

Preheat the oven to 350 and adjust an oven rack to the middle position. In a large bowl, toss the cheeses and cornstarch together until evenly coated. In a large gratin dish (about a 2- to 3-quart dish), shingle half of the potatoes. Sprinkle the potatoes evenly with 1 1/2 cups of the cheese mixture, 1/2 tsp salt, and 1/4 tsp pepper. Top with the remaining potatoes, shingling them neatly and evenly. Sprinkle another 1/2 tsp salt and 1/4 tsp pepper evenly over the top.

Combine the cream and the broth in a large measuring cup and pour the mixture over the potatoes. Top with the remaining cheese mixture and bake until golden brown and a fork inserted into the center slides in easily with little resistance, 75 to 85 minutes. Let the potatoes cool for 10 minutes. Serve.

The key to this dish is the evenly sliced potatoes. A slicing disk on a food processor/shredder works great for 1/4 inch slices.

1. http://www.melskitchencafe.com/2010/11/cheesy-au-gratin-potatoes.html

2. https://tastesbetterfromscratch.com/potatoes-au-gratin/