Sweet potatoes are a must on some holiday menus. This make-ahead dish is topped with a savoury crumble.
After mashing potatoes, turn into pan. Prepare crumble topping. Place in a plastic bag and seal. Cover potatoes in pan with plastic wrap, then foil. Refrigerate up to 2 days or freeze potatoes and topping up to 1 month. Before baking, defrost in fridge overnight or in microwave, stirring often. Bake at 350F (180C) without topping until warm, 20 to 30 minutes. Stir potato mixture. Sprinkle with crumble topping. Bake until golden, 50 to 60 minutes.