In this paper, we propose an approach for assisting educators in deriving lesson plans for complex learning subjects like Model-Driven Engineering (MDE) from existing educational materials, leveraging generative AI techniques. Our method focuses on guiding teachers in defining learning objectives and suggesting concrete learning activities for students. Central to our approach is the development of a metamodel that characterizes the methodology and serves as the foundation for implementing supporting tools. By utilizing available Open Educational Resources (OERs) and incorporating them into specific learning activities, our method provides a general framework for supporting educators in designing lesson plans. We present the methodology to generate lesson plans, the metamodel conceptualizing plans ingredients, and demonstrate their application through supporting tools, illustrating the potential of our approach in facilitating the development of MDE teaching materials.