Ingredients :
500 g white fish (cod for example)
2 medium Leek, sliced
450 ml Milk, Skimmed
2 1/2 tablespoons Margarine or butter
40 g Flour
50 g Cheese
1 teaspoons (heaped) Mustard, Wholegrain
50 g Breadcrumbs
1 sprig(s) Thyme, Fresh
1 pinch Salt
1/2 teaspoons Black pepper
Preparation:
Preheat a medium grill. Put 4 individual gratin dishes or one large shallow baking dish in the grill compartment to warm.
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.
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.