Put the drained black rice in a saucepan, poor plenty of boiling water over the rice, add the salt and cook the rice according to the package directions so they still have "a bit of a bite". The Italian black rice that I use doesn't need soaking and is perfect after cooking for 16 - 17 minuttes.
Rinse the cooked rice with cold water in a sieve, drain it thoroughly then pour into a bowl.
Add the chopped walnuts, cranberries and red onion.
Mix the ingredients for the vinaigrette and poor over the rice salad.