Delia Smith's Avocado Vinaigrette

A ripe, buttery textured avocado pear served with a really good vinaigrette is simplicity itself.

1. 1

   If they look sound, then just replace the halves together and wrap in clingfilm.
   
   To serve, split the avocados in half and remove the stones.
   
   If at all possible, don't do this until just before serving because they do tend to discolour quickly.
   
   Serve each half on a crisp lettuce leaf (if it won't sit straight, make a depression on the underside with your thumb, and this might help), spoon some of the vinaigrette into the hollows left by the stone and sprinkle with the chives.
   
   Have some extra dressing on the table along with some crusty bread and creamy butter.
   
   For the vinaigrette:
   
   I like to start off with a pestle and mortar: first of all crush the flakes of rock salt to a powder, then add the peeled clove of garlic and pound that together with the salt - which will immediately bring out its juices and turn it into a smooth paste.
   
   Next, add the mustard powder, vinegar and some freshly milled pepper, and mix thoroughly until the salt dissolves.
   
   Finally, add the olive oil and, just before dressing the salad, pour everything into a screw-top jar and shake vigorously to get it thoroughly blended.
   
   I think salad dressings should be made as fresh as possible. So if you happen to have some left over, use it the next day but don't keep it any longer.