You can teach learners some metacognition skills while making sure that they’re listening to your lecture. Though remember to always keep these teacher talk fests short! For example, my professor in college used this graphic organizer during her language teaching policy lecture:
Lessons on educational policy are usually dense so this organizer helped us take note of the important details, compare and contrast their developments right away, and get a sense of the historical progression of language policies in the Philippines.
You can use this for your summarizing activity as well. At the end of your lecture, you can run through the chart by asking volunteers from the class to read what they wrote on each cell and call on others who wrote down different details. This way the whole class are checking and supplementing their individual learning.