Add the cornmeal in a thin stream, stirring constantly. Lower the heat to a simmer, season with salt and cook 5 to 7 minutes, until the consistency of thick oatmeal.
Pour the polenta into a clean but not greased 9 by 13-inch baking dish and allow to cool 30 minutes.
Meanwhile, in a 12 to 14-inch skillet, heat 1 tablespoon olive oil over high heat until just smoking.
Add the sausage and cook over high heat until it begins to brown in its own fat.
Drain the excess fat and stir in the garlic, onion, carrot, 1/2 of the thyme, 1/2 of the oregano, fennel seeds, white wine and tomatoes and bring to a boil. Reduce heat to a simmer and cook, uncovered, 20 minutes, until mixture has a thick ragu consistency. Stir in the remaining thyme and oregano.
Meanwhile, preheat the grill or broiler.
Cut the polenta into quarters, then halves each quarter diagonally to make 8 wedges.
Brush the wedges with remaining 1 tablespoon olive oil, set over the grill and cook until slightly charred and crispy, about 10 minutes.
Divide the polenta wedges equally among 4 warmed dinner plates, top with a ladle of the ragu and serve immediately.
