Heat 1 tablespoon of olive oil in a cast iron skillet over medium-high heat.
Add the Italian sausage and break it into crumbles. Add the sliced mushrooms and crushed red pepper flakes and cook, stirring often for 4-5 minutes, or until the sausage is cooked through and the mushrooms are starting to soften.
Add the minced garlic and cook, stirring constantly, for 1 minute.
Add the can of whole tomatoes then break the tomatoes down with your spoon. Bring to a slight boil then reduce the heat and simmer for an hour, stirring occasionally.
Taste the sauce after an hour and season with a pinch of sugar (if needed) and sea salt and freshly cracked pepper, to taste. Stir in the fresh basil.
Preheat the broiler.
Heat the remaining olive oil in a skillet over medium-high heat. Add the slices of polenta to the pan and lightly season them with a bit of sea salt and freshly cracked pepper, to taste. Cook for a few minutes on each side until golden brown.
Place the golden brown polenta on top of the Italian sausage sauce then sprinkle with some shredded mozzarella. Place under the broiler until the cheese is browned and bubbling, about 2-3 minutes.
Top with freshly grated parmesan cheese and more fresh basil. Serve and enjoy.