Halve the baby potatoes and cook in a large pot of salted, boiling water until cooked. (The potatoes are cooked when a knife's tip can easily be inserted.)
Drain the potatoes and allow to cool slightly.
To make the dressing, mix the sour cream and seasoning and thin out with a little milk or water if necessary.
Pour the dressing over the cooked potatoes and mix. (Adding the dressing to the potatoes while they are still warm will allow the potatoes to absorb the dressing.)
Taste and adjust the seasoning if necessary then allow to cool completely before serving.