Fish parcels

Name: Fish parcels
Cuisine: European, Mediterranean
Ingredients: 1 piece chunky white fish fillet, skinned (approx. 125g); 1 small leek, finely sliced; 1 x 215g can butter beans, drained and rinsed; sprig parsley, chopped; 1 tbsp reduced-fat crème fraîche mixed with 1 tbsp stock; freshly ground black pepper