Preheat oven to 350 F.
Bring 4 cups of water to a boil and add 1 cup cornmeal, whisking constantly.
Add 1⁄2 tsp salt and reduce heat to low. Continue to cook for 30-35 minutes. Whisk occasionally, making sure to scrape edges/bottom of pan to avoid sticking. Remove from heat.
In a large sauté pan over med-high heat, cook the following for ~12 minutes: 1 # ground turkey (break apart as you cook), 8 oz sliced mushrooms, 2T Italian seasoning.
Stir in ~24oz jar of spaghetti sauce, remove from heat.
Grease a 9x13 pan w/ olive oil.
Assemble by layering in a 9x13” pan:- 1/3 turkey tomato sauce- layer of polenta (spread with a knife)- 1/3 turkey tomato sauce- layer of polenta- remaining turkey tomato sauce Sprinkle w/ 1⁄2c parmesan cheese, optional
Bake for 30 mins, covered, or until bubbly. Cool ~10min.