Teacher education is essential in every stage of a teacher's career, especially at the start as it provides a strong foundation in pedagogy, theoretical knowledge, and reflective attitudes. In this paper, a custom OpenAI GPT is presented that generates educational scenarios with possible students' questions and gives feedback to science teachers' answers and educational approaches. Furthermore, a pilot study was carried out that measured the self-concept of the science teachers and showed that the influence of the aforementioned GPT-teachers interaction had a positive impact on teachers' self-concept, indicating an interesting way generative AI tools can be a valuable educational partner.