Rinse leaves and pat dry on kitchen paper before roughly chopping.
Pack the chopped leaves into a sterilised jar.
Top up the jar with olive oil.
Pop on a secure lid and shake well.
Set aside in a cool dark cupboard for 2 weeks shaking every day or so.
Strain the oil through a sieve lined with muslin/cheesecloth or paper towels.
Decant into a sterilised bottle.
Store in the fridge for up to 3 weeks.