Ingredients
Method
Preparation and Baking Potatoes
- Preheat the oven to 400°F. Scrub the potatoes, dry them, prick them with a fork, wrap in foil, and bake for about 1 hour 15 minutes until tender. Let cool to room temperature, then refrigerate overnight.
Prepare Aromatics
- Heat oven to 400°F again. Butter a 2-quart baking dish. Melt 3 tablespoons of butter in a saucepan over medium-low heat, add shallot, cook until soft, then add garlic and cook until fragrant.
Grate and Mix Potatoes
- Grate the chilled potatoes with skins on into a large bowl. In another bowl, whisk together sour cream, salt, white pepper, cheddar, and the shallot-garlic mixture. Fold the grated potatoes into the mixture until just combined.
Assemble and Bake Casserole
- Spread the potato mixture in the baking dish, topping it with Parmesan and remaining cheddar. Bake for 25-30 minutes until golden brown and hot.
Rest and Serve
- Let the casserole rest for 10 minutes before serving. Optionally, finish with minced chives.
Make Ahead and Storage
- Assemble up to 48 hours in advance, refrigerate covered. Bake from room temperature for 30-35 minutes if assembled ahead.
Notes
For best texture, bake potatoes the day before and chill overnight. Adjust salt according to cheese saltiness, and avoid overmixing after adding potatoes.
