This chapter introduces a practical example to support K-12 pre-service teachers in designing and implementing inquiry-based STEM learning activities with the support of generative AI (GenAI). The chapter demonstrates how GenAI can be used as a facilitator of student inquiry—encouraging exploration and reflection, and supporting collaboration. Through a structured process, pre-service teachers learn how to design open-ended prompts, co-create rubrics, and scaffold student-driven investigations using GenAI tools. A step-by-step classroom implementation example simulates a GenAI–student interaction, modeling how the tool can guide inquiry while promoting student autonomy and critical thinking. Rather than focusing on technical tool training, the chapter emphasizes pedagogically grounded strategies for using GenAI in ways that align with inquiry learning principles. This approach equips future educators with a replicable and creative framework for integrating emerging technologies into student-centered STEM education.