Facilitating the transition of STEM teachers into the teaching profession represents an important challenge in teacher education. We argue that it is those aspects of excellent teaching that beginning teachers believe to be important that may be the central foci for teacher preparation. In the context of the nationally replicated UTeach program, we explore how beginning UTeacher's beliefs about important instructional approaches (Study 1) relate to observed classroom practices (Study 2). UTeachers valued classroom practices such as: designing engaging, inquiry-based activities in real-world contexts; responding flexibly to student needs by modifying instruction, differentiation, and using questioning strategies; and effectively communicating content. However, UTeachers showed limited mastery of some practices--they were successful at designing engaging activities but struggled with in-the-moment teaching behaviors such as higher-level questioning and modifications. We also found that while UTeachers reported valuing their content knowledge, they sometimes had difficulty effectively translating their content expertise into a K-12 teaching context.