Wash the chipotle chillies, remove the hard stems (leave the seeds in) and place them in a bowl. Pour over 150ml/5fl oz just-boiled water, cover with cling film and soak for about 20 minutes.
You can buy chipotles in adobo (or in a tomato-based sauce) in a tin, or you can buy them dried from online retailers and make your own paste. A homemade paste will pack far more punch as you will ...