Grate the courgette and cover with plenty of salt. Leave it to draw out the moisture while you measure out the rest of the ingredients.
Line a large swiss roll tin (23x30cm) with non-stick baking paper. Get a good fit so that you can get right into the corners with the mixture.
Grate the cheese.
When the courgette starts to show the water coming out, squeeze it in a clean tea towel to get it as dry as possible.
Mix the flour and baking powder together thoroughly first.
Beat the eggs and milk together and then add all the other ingredients and mix well.
Tip in to the swiss roll tin and level it all out. It will look like there's not enough mixture, but it needs to go very thin. Just spend a bit of time getting it even and covering over any holes.