Elizabeth Zott, a former research chemist with a commanding presence, discovers why her daughter Madeline is losing weight: Madeline has been surrendering her elaborate, nutritious lunches to classmate Amanda Pine to maintain a fragile friendship. Reasoning through other causes, Elizabeth identifies Amanda as the culprit.

Elizabeth storms into the local TV studio to confront Amanda’s father, producer Walter Pine. She bluntly accuses him of enabling his daughter’s behavior and emphasizes that food drives cognition and futures. As Elizabeth departs, her remark about teaching the nation to make food that matters triggers Pine’s inspiration.

Four weeks later, "Supper at Six" launches. Elizabeth’s serious, unsmiling style and hearty, efficient recipes stand out, rapidly building a devoted audience—even Vice President Lyndon Johnson watches. She stresses the four food groups and speed, ending each show: "Children, set the table. Your mother needs a moment to herself."

With success comes reductive branding. A reporter dubs her "Luscious Lizzie," a nickname that belittles her expertise, frustrating Madeline and shaming Elizabeth. Lying awake, Elizabeth wonders how she arrived here, then concedes she knows: Calvin Evans set her on this path.