Sue Gale served great scalloped potatoes to Janet and me so I asked for her recipe. She kindly provided it so now you have it too. It is "Delish!" The key to making excellent scalloped potatoes is to slice the potatoes and onions very thin, using a mandolin or a very thin setting on a food processor. Also, be sure to bake this food in a cast iron or stoneware baking dish that has a lid and is no more than 2" deep. Either will cook the food better than other types of baking dishes and the food will be less likely to burn. At the end of the baking cycle the dish should be moist within but without much remaining liquid.
1 cup of Whole milk
4 tbsp. of Butter
4 medium Russet potatoes
1 medium yellow or sweet onion
Set the oven temperature to 300ºF.
Slice the potatoes and the onion thinly (about 1/16th of an inch thick) using a mandolin or a thin setting on a food processor. I prefer the food processor as it is very fast, safe and not labor intensive. Rinse the potato slices in lots of cold water and then dry them, one layer thick on a dish towel, with a second dish towel on top. Press lightly. Repeat as necessary with the rest of the potato slices.
Layer the potato, onion, very thin slices of butter (three or four per layer) and continue until the dish is full or the materials consumed. Season each layer very lightly with salt and pepper.
You can overload the dish slightly, if necessary, with an extra layer of potato and onion slices that is higher than the edge of the dish, as the mixture will sink as it bakes.
When all of the layers are complete, add the cup of whole milk.
Cover the dish with the lid and bake until the potatoes are tender, about one hour.
Reduce the oven temperature to 275ºF and bake with the lid off to reduce the fluid contents for about 30 minutes. The top should be a light golden brown in color.
Serve. You will get many compliments.
Adding slices of cheese products like Velveeta® to this dish, especially on the top, turns it into potatoes au gratin with onions. Other cheeses like soft provolone can also be used.
The cheese can also be layered within the dish with the potatoes and onions.