If I had used large potatoes then the casserole would never have fit into the baking dish. Just grab a square casserole dish and follow these easy steps. The recipe would be easier to follow if the size of the potatoes had been given. Bake â¦ Mix until everything is combined. Using a mandoline or slicer, slice potatoes into 1/8-inch slices (very thin.) Layer 1/3 of the potato slices in the buttered casserole dish. The recipe states to use 5 potatoes without mentioning what size and one onion without saying large onion or small. Top the layer with ham. Melt butter in microwave in large bowl. Mix in condensed soup, sour cream, and cheese. Making this casserole is as easy as it gets! Grab a large bowl and toss in your ham, some frozen potatoes, shredded cheese, cream of chicken soup, and some sour cream. How to Make Ham and Potato Casserole. 6 medium potato, peeled and thinly sliced (about 6 cups) 1 medium onion, chopped (about 1/2 cup) 2 cans (10 1/2 ounces) Campbellâs® Condensed Cream of Mushroom Soup or 98% Fat Free Cream of Mushroom Soup 2/3 cup water Spread one half of the potato mixture on bottom of 13 x 9 casserole dish. https://www.yummly.com/recipes/cheesy-potato-casserole-with-ham Pour in potatoes, coat well. Spread remaining potato mixture over the ham. Sprinkle on 1/3 of the ham/onion mixture, then 1/3 of the cheese, then pour on 1/3 of the cream mixture.