Ingredients

2 tablespoons unsalted butter, softened 

2 medium shallots, very thinly sliced (about 1/2 cup) 

Coarse salt and freshly ground pepper 

4 ounces sorrel, tough stems removed, cut crosswise into 3/4-inch pieces (about 3 cups) 

1 1/2 pounds new potatoes, preferably German Butterball or Yukon gold, peeled and cut crosswise into 1/8-inch-thick rounds 

1 1/4 cups heavy cream 

Preparation

Preheat oven to 350 degrees. Coat an 8-inch square baking dish with 1 tablespoon butter. Arrange shallots in an even layer over bottom of baking dish. Season with 1/2 teaspoon salt and 1/4 teaspoon pepper.

Arrange half of the sorrel over shallots, then layer with half of the potatoes. Season with 1/4 teaspoon salt. Repeat with remaining sorrel and potatoes. Season with 1/4 teaspoon salt and 1/4 teaspoon pepper. Pour cream over top, and dot with remaining tablespoon butter.

Cover with foil; bake 1 hour. Uncover; bake until potatoes are tender and cream is thick, about 20 minutes more. Let stand 15 minutes before serving.