While consensus on the importance of deliberate practice (DP) in psychotherapy increases, clarification of key elements in DP supervision is yet to be seen. An international collaboration between researchers, authors, supervisors, and therapists has proposed a method for DP supervision and created a training program for DP supervisors. This has led to a six-step overview model for DP and the DP Supervisor Competency Rating Scale (Vaz, Rousmaniere and Husby, 2023). DP in the context of supervision has concrete steps and requires specific supervisor skills. This article illustrates these with a case study consisting of twelve sessions with a supervisee that is a seasoned clinical psychologist and a trained DP supervisor. Annotated session transcripts provide a step-by-step qualitative representation of the collaborative process in identifying client challenge, therapist deficit and actionable learning goals as well as the in-session behavioral rehearsal. The article presents the DP-supervision overall trajectory, as well as both supervisee´s and supervisor´s input on the process. It discusses the importance of integrating conceptual, conditional, and procedural knowledge in therapist development, and claims that the same is true for DP-supervisor development. Finally, the need for empirical investigation of the proposed key elements in DP supervision is emphasized.