Ingredients

• 2 cups (lightly packed) 1/2-inch cubes French baguette with crusts
• 2 tablespoons (1/4 stick) butter
• 2 tablespoons vegetable oil
• 1 pound russet potatoes, peeled, cut into 1/2-inch cubes
• 1/2 cup finely chopped shallots
• 1/2 pound hot-smoked salmon fillets, skinned, flaked into bite-size pieces
• 3 tablespoons minced fresh chives
• 2 teaspoons minced fresh dill
• 4 large eggs
• 1 cup half and half
• 3 tablespoons sour cream
• 1 teaspoon Dijon mustard
• 1/2 teaspoon salt
• 1/4 teaspoon ground black pepper
• Additional sour cream
• Capers
• Fresh dill sprigs

Instructions

1. Preheat oven to 400°F. Arrange bread on rimmed baking sheet. Bake until pale golden, about 5 minutes, then cool.
2. Butter 11x7-inch glass baking dish. Melt 2 tablespoons butter with oil in heavy large skillet over medium-low heat. Add potatoes. Stir to coat and arrange in single layer. Cover and cook until potatoes are almost tender, about 8 minutes. Uncover; increase heat to medium-high, and cook until potatoes are lightly browned and tender, stirring occasionally, about 5 minutes. Add shallots and sauté until soft, about 2 minutes. Remove from heat. Gently mix in bread, salmon, chives, and minced dill. Transfer mixture to prepared dish.
3. Whisk eggs and next 5 ingredients in medium bowl to blend well. Pour custard over potato mixture in dish. Let stand 15 minutes, occasionally pressing bread into custard. (Can be made 1 day ahead. Cover; chill. Let stand at room temperature 30 minutes before baking.)
4. Preheat oven to 350°F. Bake casserole, uncovered, until custard is set, about 30 minutes. Cut into squares and top with additional sour cream, capers, and dill sprigs; serve hot.