Tom Douglas' Potato-Turnip Gratin
Ingredients
- 3 tablespoons unsalted butter, divided
- 1/4 cup chopped Italian parsley
- 2 teaspoons each chopped fresh rosemary, fresh sage, fresh thyme
- 4 large Washington Russet potatoes
- Kosher salt and freshly ground black pepper
- 1 cup (4 ounces) freshly grated Parmesan cheese, divided
- 1 cup heavy cream, divided
- 2 cups 1/8-inch thick peeled turnip slices