Peel and dice the sweet potato. Put in a saucepan and cover with water. Bring to the boil then simmer for 10-15 minutes or until tender.
Steam/boil the broccoli and green beans for 5-7 minutes or until tender.
Blend the sweet potato, broccoli and green beans until the desired consistency is reached.
Place the fish in a suitable microwave container, dot with butter and add 2 tablespoons of milk, cover and cook on high for 2 minutes or until the fish is cooked (alternatively, poach the fish with the milk in a saucepan for 5 minutes or until the fish is cooked).
Flake the fish in a dish to make sure there are no bones present.
To make your sauce, melt the butter, stir in the flour and cook over a low heat for 1 minute. Gradually stir in 300ml milk. Bring to the boil and simmer, stirring until thick and smooth. If too thick add more milk.
Mix the white sauce, cod and vegetables together.
Suitable at 6+ months