Chop cherry tomatoes, a small bulb of fennel, a garlic clove, half a stick of celery, and a small amount of red onion (half a shallot also works well) and place into a blender with a few torn basil leaves, a few drops of tabasco and a dash of Worcester sauce.
Pulse a few times until you have a puree and then transfer to a bowl, cover with clingfilm and refridgerate for six hours or overnight.
Line a clean bowl with muslin and pour the puree into it.
String the muslin up over the bowl and leave overnight to strain - do not squeeze the bag!
Once strained serve with a little chopped tomato and parsley or refriderate until needed.