Pre-heat the oven to 200°C. Place the saffron in a tea cup, pour over 2 tablespoons of hot water and leave to soak.
Put the potatoes in a pan of boiling salted water and par-boil for 7 minutes. Drain well and arrange them in a narrow strip over the base of a roasting dish large enough to hold the sea bass either lengthways or diagonally. The potatoes should form a bed for the fish, leaving plenty of room on either side for the red peppers.
Scatter the tomatoes and anchovy fillets over the potatoes, then pour over the saffron water and stock. Scatter the pieces of red pepper down either side of the potatoes and sprinkle over the garlic, oregano
sprigs and olive oil. Season everything well with salt and pepper and bake in the oven for 30 minutes.
Slash the fish 5-6 times down each side and then slash it in the opposite direction on just one side to give an attractive criss-cross pattern. Rub it generously with some olive oil, season well with salt and
pepper and then rest it on top of the potatoes.
Return the dish to the oven and bake for a further 35 minutes, until the fish is cooked through. Serve with the roasted vegetables.