Overview: Martha offers a primer on this favorite starch. She begins with Scalloped Potatoes, also known as Potatoes Gratin: thinly sliced potatoes cooked in milk and baked in a cream mixture with cheese. Next comes a recipe that’s become synonymous with American food: Potato Salad. Then, in case your go-to mashed potato recipe needs an upgrade, Martha shows a few tricks to achieve the perfect Puréed Potatoes. Finally she shows how, in just a few easy steps, anyone can make Smashed Potatoes — crispy on the outside, creamy on the inside.