Preheat the oven 220°C (425°F gas mark 7).
Parboil the new potatoes for 5 minutes, then drain. Place in a non-stick oven tray and mix with olive oil and rosemary, season with salt and pepper and place in the oven for 20 minutes.
Score the skin of the sea bass with a sharp knife, rub with olive oil and season with salt and pepper. Place on a non-stick baking tray and place in the oven for 15 minutes. The fish is cooked when the flesh comes away from the bone with ease.
In the meantime, bring a medium sized pan of salted water to the boil.
When the potatoes and sea bass are cooked remove from the oven and keep warm.
Place the Tenderstem in the boiling water, cook for 1 minutes and drain.
Divide the fish, potatoes and Tenderstem between 4 plates.
In the tray that the fish was in heat the butter until it starts to brown, add the garlic and anchovies and cook for 30 seconds. Stir in the parsley season with pepper (do not add more salt as the anchovies are preserved in salt).
Pour the butter over the fish and Tenderstem and serve with a wedge of lemon.
Recipe courtesy of Tenderstem Broccoli