Creamy white fish and leek gratin

8 SmartPoints® per serving Prep time: 10 min Cook time: 15 min Serves: 4

Ingredients
​500g cod, raw    
2 medium Leeks, sliced    
450ml skimmed milk    
2½ tablespoons soft margarine
40g plain white flour    
50g Cheddar cheese, grated    
1 heaped teaspoon wholegrain mustard    
50g fresh breadcrumbs
Sprig fresh thyme
Pinch salt and black pepper 

Instructions

1. Preheat a medium grill. Put 4 individual gratin dishes or one large shallow baking dish in the grill compartment to warm.
2. Put the fish and leeks into a large frying pan and cover with water. Heat and simmer gently for 5-6 minutes, or until the fish is just cooked. (The flesh should flake easily when tested with a fork). Drain thoroughly then share the fish and leeks between the warm dishes.
3. Put the milk, margarine and flour into a non-stick saucepan. Heat, stirring constantly with a small whisk until the sauce boils and thickens. Remove from the heat. Stir in the mustard and half the cheese. Season and pour over the fish. Scatter the breadcrumbs, thyme or rosemary sprigs and remaining cheese over the top. Grill for 3-4 minutes, until browned and bubbling. Serve at once.