Prepare the sauce first:
Peel the onion and the garlic cloves; mince both finely.
Place the olive oil in a large stock pot and heat over medium high heat. Add the minced garlic and onion. Brown lightly, about 5 to 6 minutes stirring frequently.
Lower heat to low and add tomatoes, wine, oregano, pepper and cane sugar. Cover and let simmer for about 40 to 45 minutes, stirring occasionally.
Now prepare the polenta:
Place the water in a medium sized saucepan. Bring to a boil over medium high heat. Whisk in the cornmeal slowly in a very thin stream. If you add it too fast, it will lump. Add the butter.
Lower the heat to low and stir constantly with a wooden spoon until the mixture is very thick, about 15 to 20 minutes or until it pulls away from the sides of the pan.
Pour polenta into a serving platter and top with marinara sauce and parmesan cheese.
Serves 6 to 8