Makes 500ml/18fl oz
Use a pestle and mortar (or a bowl and the end of a rolling pin) to bruise the herb or herbs, which will help to release their flavour.
Put in a bowl or jar and add the oil. Cover and leave in a warm place such as a sunny windowsill for 2-3 weeks.
Strain through a fine sieve into a jug. Pour into one large, sterilised, thoroughly dry bottle or several smaller ones. Push a few herb sprigs down into the oil, both as decoration and to identify which herbs have been used.
Cover with screw-topped lids, clip tops or stoppers and store in a cool place for up to 6 months.