This Case Study is based on original research motivated by the lack of literature discussing national and international consensus to develop entrustable professional activities for dermatology doctoral learners. We aimed to collect experts' opinions to reach a consensus on activities expected from doctoral dermatology learners as a primary objective. This objective required implementation of a combination of survey and discussion procedures, that is, a mixed-methods Delphi technique. The Case Study focuses on why we selected a mixed-methods modified Delphi technique and how we applied this method. Furthermore, we explore the rationale beyond application of constructivist grounded theory in mixed-methods research. Readers will learn when and how they should use a mixed-methods modified Delphi method, key methodologic criteria used to report a Delphi study, and quality indicators of Delphi studies. [This content is provided in the format of an e-book.]