One task defines the role of the teacher: the communication of an idea from her soul to that of the student. Until that communication takes place, teaching hasn’t occured. Therefore, the teaching that takes place does not arise from preparing a lesson plan the week or night before, but from the teachers ongoing reading, thinking, writing, discussing, and yes, teaching.
Therefore, in a teacher interview, you should ask every teacher what they have been reading lately. If nothing is literary or from before the 20th century, you may be in trouble. Dig deeper.
The great teacher is first and foremost a learner. To not be eager to learn is to be a bad teacher, no matter how many years you have been teaching.
The role of the head is to create a world in which the teacher can fulfill her role.