In this episode, 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 thatís 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 ó crispy on the outside, creamy on the inside.