HOT SMOKED TROUT AND ROASTED CHERRY SALAD

100g cherries, halved • 20g walnuts • 250g pack cooked freekeh • 2 tbsp extra virgin olive oil • 1 tbsp cider vinegar • 60g pack watercress, rocket and spinach salad • 2 hot smoked rainbow trout fillets • 1 tbsp creamed horseradish sauce • 2 tbsp reduced fat soured cream