The ultimate makeover: Fish pie

Name: The ultimate makeover: Fish pie
Ingredients: 500ml semi-skimmed milk; 3 tbsp cornflour; 100g cooked prawns in their shells; several thyme sprigs, preferably lemon thyme; 2 bay leaves; 1 garlic clove, thinly sliced; 750g new potatoes, such as Charlotte (no need to peel); 1 medium leek, thinly sliced (175g prepared weight); 400g skinned haddock fillet; 350g skinned salmon fillet; 175g skinned smoked haddock fillet; 125g tub low-fat soft cheese with garlic & herbs; 2 tbsp finely chopped parsley; 2 tbsp olive oil; 2 tbsp snipped chives