In this paper we reviewed what 49 large urban public school district STEM teachers enrolled in a year-long graduate certificate and fellowship program at a large Midwestern university considered as their amazing teaching moments. They were asked to share their amazing teaching moments that would make an Ultimate Lesson Plan in STEM. In smaller groups of five, then they were asked to find connections between their amazing teaching moments and to look for the essential components that make these moments amazing. This activity led the teachers to discover 51 key components that made an ultimate lesson plan. We analyzed these 51 key components to find common and overarching themes that were grouped together into a final list of seven key components for an ultimate STEM lesson plan. These key components that make an ultimate STEM lesson plan give us an insight into what working teachers consider to be important for student engagement and learning in STEM content in classrooms.