A recent Government response to shortages of new physics and chemistry teachers is the extended subject knowledge enhancement (SKE) course. Graduates without a physics or chemistry bachelor degree are prepared by an SKE course to enter a Postgraduate Certificate in Education (PGCE) programme to become science teachers with a physics or chemistry specialism. SKE courses challenge common assumptions about the nature of subject knowledge for teaching and who should teach it: school science educators or scientists? This article shares the SKE course model developed and taught by the Science Education team at Liverpool John Moores University, and some early insights into supporting subject knowledge development. (Contains 1 figure and 2 tables.) (Contains 2 tables and 1 figure.)