. Line a 9 x 13 pan with parchment or wax paper and have ready for the polenta.

Make tomato sauce.  In large saucepan, heat 2 tablespoons oil over medium heat.  Add onion and cook until softened, about 10 minutes.  Cook in minced garlic for a minute and then immediately add tomatoes and stir.  Add wine, whole sausages, thyme sprigs and 1/2 teaspoon salt.  Bring sauce to a gentle simmer and cook, uncovered, stirring occasionally, until reduced, about 30 minutes or until sauce consistency. Cover when ready.

While tomato sauce is cooking, prepare polenta. In a large saucepan, combine water, 2 tablespoons oil and 3/4 teaspoon salt; bring to a boil.  Lower heat to medium-low. Slowly add cornmeal in a steady stream, whisking constantly.  The mixture will start to become thick. Continue to whisk and add 1/4 cup of water at a time if necessary to prevent sticking. After a few minutes, test polenta for doneness.  The grain should be soft. Cool a spoonful and taste it. When done remove from heat immediately.. Coarse polenta may need longer to cook.

When polenta is cooked, immediately pour it into the prepared pan lined with parchment and spread evenly with a rubber spatula.  Set aside to cool until the polenta is somewhat solid. Heat oven to 400°.

Lightly grease a rimmed baking sheet. When tomato sauce is ready and polenta has cooled, invert baking sheet over the polenta pan and flip it over so that the parchment paper is on top and you can peel it off.

Remove sausages from tomato sauce and slice into 1/2" thick rounds.

Top polenta with some of the tomato sauce, spreading sauce to 1/2" from edges of polenta. (Continue to simmer remaining sauce covered for another 15 minutes or until ready to serve.) Arrange sausage and cheese on top.  Bake until cheese is melted, about 10 minutes.  Cut into squares and serve warm with more tomato sauce, a drizzle of olive oil and fresh ground pepper.