Boil unpeeled potatoes until tender. Cool and peel then shred using medium grater. Shred cheese with same grater.
Butter or spray a 9x13 pan. Alternate layers of potatoes starting with one third of the potatoes: then add half the cheddar cheese. Repeat both then finish with a final layer of shredded potato. Sprinkle salt and pepper over each layer.
Pour whipping cream slowly over potato-cheese layers. Sprinkle with panko bread crumbs.
Refrigerate, covered, several hours or overnight. Bake, uncovered, in a preheated 350 °F oven until heated through (55-65 minutes). Let set at least 10 minutes prior to serving.