1 yellow onion, peeled
4 garlic cloves
salt and pepper
1-2 pounds Italian pork sausage, sweet or hot
8 1/2 cups water
2 cups polenta
1 tsp chopped fresh rosemary
3 TBS butter
3/4 cup pitted Kalamata olives
1 1/2 TBS chopped flat-leaf parsley
In a heavy pot over high heat, combine the tomatoes, onion (whole) and garlic cloves. Bring to a boil, reduce the heat to low and simmer, uncovered, for about an hour. Remove from the heat and discard the onion. Puree with an immersion blender or food processor. Season with salt and pepper.
Prick the sausages with a fork. In a large pan, bring 1/2 cup water to a boil. Add sausages and cook over medium-high heat until golden on all sides and half cooked, 10-12 minutes. Drain and cut on the diagonal into 1-inch pieces.
In a large, heavy saucepan, bring the remaining 8 cups water to a boil over high heat. Slowly add the polenta in a steady stream while whisking constantly. Continue to whisk until the mixture thickens, 3-4 minutes. Reduce heat to medium and simmer, stirring constantly, until the polenta pulls away from the sides of the pan, 20-25 minutes. Stir in the rosemary and butter. Season with salt and pepper.
Place the pureed sauce over medium heat and bring to a simmer. Add the sausage pieces and olives and simmer, uncovered, until the sausage pieces are cooked through, about 10 minutes.
Top the polenta with the sauce, shaved cheese and parsley.