Courgettes are easy to grow but can be ridiculously prolific. This recipe adapted from one in Giles Rose’s A Perfect School of Instructions for the Officers of the Mouth (1682), is a great way to use up a glut of courgettes, and can be frozen. If you cook courgettes long and slow they virtually melt into the butter and need very little stock to produce a soup (I picked this tip up from fellow food writer Kathy Slack’s