1) Cook the beans as per the instructions on the packet and drain the beans well .
2) In a saucepan, stir in the flour, pepper and salt in the 2 tbsp melted butter or margarine.
3) Pour the milk into the saucepan, stir well and cook until thick and bubbly.
4) Blend in the blue cheese and spoon the sauce over the cooked beans.
5) Gently toss the cornflake crumbs with 1 tbsp melted butter and sprinkle evenly over the beans.