In a medium saucepan bring water to a boil, add polenta, basil, salt and tomatoes, stirring constantly. Reduce heat and simmer for about 45 minutes until very thick; stir at least every 5 minutes.
Pour and scrape polenta onto a buttered platter, cool about 3-5 minutes. Cut into squares. Heat grill and grill for 2-4 minutes on each side. Top with crumbled Gorgonzola cheese; heat under broiler until cheese is melted (watch closely). Top with freshly chopped basil.