- 4 tablespoons butter or oil
- 1 cup bread crumbs or 1/2 cup grated Parmesan cheese for the pan
- Scant 2 pounds Yellow Finn or Yukon Gold potatoes, peeled and chunked
- Sea salt and freshly ground pepper
- 2 garlic cloves
- 4 eggs, lightly beaten with a little water
- 3 tablespoons chopped sage
Preheat the oven to 375°F. Put a 10-inch cast-iron skillet in the oven with a tablespoon of the butter until melted. Brush it around the pan, then scatter bread crumbs or Parmesan cheese into it to make a crust for the potatoes.
Drain the potatoes and return them to the pot. Add the garlic and remaining butter and mash. Taste for salt and pepper, making sure the potatoes are highly seasoned. Then stir in the eggs and sage, transfer the mass to the skillet, and smooth the top. Bake until golden and pulling away from the sides of the pan, about 45 minutes. Remove, let stand for 10 minutes, then run a knife around the edge and unmold onto a serving plate.