Cut the smooth potatoes into chunks and place in a large saucepan with the garlic, cover with water and bring to the boil. Simmer for 15-20 minutes or until tender, drain and return to the pan.
Meanwhile, bring a separate pan of water to the boil and remove from the heat. Season the cod and spread each fillet with 1/4tsp Dijon mustard. Wrap each fillet in cling film and add to the pan of water. Set aside.
Mash the potatoes with the milk, butter and remaining mustards and season to taste.
Place the pan with the cod on a medium heat for 1-2 minutes or until fish is cooked.
Serve the cod with the mash and garnish with a sprinkling of chopped parsley and freshly cooked French beans.
To roast the cod, place on a baking tray and season. Spread each fillet with ½ tsp Dijon mustard. Bake for 10-15 minutes at 180C, gas mark 4 or until cooked. Serve with roasted cherry or vine-ripened tomatoes. Just drizzle with oil and pop in the oven at the same time as the cod for 10-15 minutes.
750g Smooth potatoes
1 clove garlic
4 cod fillets3 tbsp Dijon mustard1 tbsp French mustard
100ml milk25g butter (optional)