Creamy Potato Recipe

I have no idea what these are really called. They serve them a restaurant in Utah. I can't remember the name of the place. Anyhoo...Mary gave me this recipe and we made it for Christmas dinner and they were awesome. I'm not sure how many lbs of potatoes I actually used and the recipe is kind of vague about it, but I think I used 5 or so large potatoes. Just enough to fill an 11 x 14 glass pan. Helpful I know, but so worth figuring it out. :)

11 x 14" glass pan
10 lbs Uncooked Potatoes (you won't use them all)
1.5 qt. Heavy Whipping Cream (Marigolds Cream)
1 Tbsp Salt
1 1/2 tsp White Pepper (1 Tbsp for spicy)
1/2 Cups Corn Starch (1/3 for creamier mix)

Peel potatoes and cut into thin slices like Au Gratin style and fill medium sized pot until 3/4 full. Fill pot with enough water to cover potatoes. Bring to a boil. Cook until they are almost thoroughly cooked (cooked but firm). Preheat oven to 380 degrees. When potatoes are put into the water to boil pour chilled Whipping Cream in a different pot and then blend in corn starch with a whisk as you pour in the corn starch. Add Salt and white pepper to whipping cream. Cook whipping cream mixture on medium to low heat until it is the consistency of gravy (it is a dairy product so it can burn easily so keep low and stir continually). Do not over cook potatoes. When potatoes are done put in pan and when whipping cream is done pour over potatoes (best if potatoes are still hot) so they are completely covered and slightly mix in. Cover with foil and cook for 1 hour.