This is simple and very good! The potatoes are best when cooked and completely chilled before slicing and using in this recipe, so if possible make the potatoes a day ahead, cover and refrigerate overnight.
- Cook the potato halves in boiling salted water until just firm tender.
- Let cool to room temperature then chill until completely cold.
- When potatoes are cold slice about 1/3-inch thick (or a little larger).
- Set oven to 350 degrees.
- Butter a 13 x 9-inch casserole dish.
- Layer half of the chilled sliced potatoes in the bottom of the buttered dish, sprinkle with salt and pepper on top.
- Then sprinkle with half of the onion, then half of the Velveeta cheese.
- Repeat the layers.
- Drizzle with the whiping cream, then sprinkle with grated Parmesan cheese on top.
- Bake for about 50 minutes.