Combine hazelnut oil, olive oil, safflower oil, apple cider vinegar, shallots, lemon juice, salt and pepper.
Fold 1 tbsp of chives through the sour cream. In a bowl mix radicchio, kipfler, sugar syrup, turnips, cornichons, chervil, dill, and remaining chives with 2/3 of the dressing. Toss prawns with remaining dressing. To assemble, divide salad between 4 plates, top with king prawns, dollop of sour cream and 1 tsp caviar.