A staple of traditional French cooking, this comforting side dish transforms everyday vegetables into something extraordinary. Sweet green peas, spring onions, and quartered lettuce hearts simmer gently in a savory chicken broth until they're meltingly tender. The butter enriches the stock, creating a light, flavorful glaze that coats the vegetables. It's an elegant yet straightforward addition to roasted meats or poultry, proving that the simplest ingredients often make the most memorable sides.