Tuna Stuffed Globe Artichoke

4 globe artichokes
salt
100 g/4 oz long-grain rice
1 x 350 g/12 oz can tuna fish .
4 tablespoons tomato puree
2 teaspoons chopped fresh basil or 1 teaspoon
dried basil
2 teaspoons chopped fresh oregano or
1 teaspoon dried oregano
salt
freshly ground black pepper

Cut off the artichoke stalks. Plunge the heads into boiling salted water. Simmer for about 20 minutes or until the bottom leaves pull away easily. Drain and leave until cold