The purpose of this documentary account is twofold. First, we describe two strategic instructional assignments embedded in university courses at a large research institution in the United States that were designed to help teaching candidates move toward mastery. Second, we explicate candidates' performances on the assessments as well as evidence of the reliability of the assessments and scoring procedures. This case study provides evidence that advanced secondary teaching candidates are able to address instructional issues and engage in the kind of pedagogical reasoning more characteristic of experienced teachers. Further, this account indicates that despite some challenges, it is feasible for multiple course instructors in a research institution to implement and score reliable, valid embedded assessments. (Contains 13 tables.)