1-Boil whole unpeeled potatoes in salted water: Boil whole unpeeled potatoes in salted water for 20-25 minutes until just tender. Drain and refrigerate overnight.
2-Peel chilled potatoes and shred using a: Peel chilled potatoes and shred using a coarse grater into a large bowl.
3-Melt butter in a skillet and sauté: Melt butter in a skillet and sauté shallots for 3-4 minutes until soft. Let cool slightly.
4-Gently fold sour cream, sautéed shallots, shredded: Gently fold sour cream, sautéed shallots, shredded cheese, salt, white pepper, and paprika into the potatoes.
5-Preheat oven to 350°F (175°C): Preheat oven to 350°F (175°C). Transfer mixture to a greased baking dish without packing tightly.
6-Top with remaining cheese and bake for: Top with remaining cheese and bake for 35-45 minutes until golden and bubbly.
7-Let rest for 10 minutes, garnish with: Let rest for 10 minutes, garnish with fresh chives, and serve.