The next time you’re tasked with bringing potatoes to the potluck, surprise everyone with this comforting Mashed Potato Casserole. Made with Yukon Gold potatoes (our favorite for mashing) and tangy Swiss cheese, it’s a tasty change of pace from plain mashed potatoes yet it will go with just about any main dish that’s on the table. (Not a fan of Swiss cheese? Swap it out for the same amount of shredded Gruyere or sharp white Cheddar.) This casserole is extra rich and creamy thanks to the addition of cream cheese, sour cream, and half-and-half. A topping of toasted fresh breadcrumbs and crispy fried onions adds the right amount of crunch to balance out the smoothness underneath. If you’re bringing this casserole to a gathering and want to make it in advance, the potatoes can be made up to two days ahead and stored in the refrigerator. When you’re ready to serve the potatoes, remove the pan from the refrigerator while the oven preheats. Prepare the breadcrumb topping, then sprinkle it on top of the casserole and bake it in the oven as directed.