For the mushrooms:
Pour the olive oil into a large skillet set over medium heat. Add the onions and garlic and cook until translucent but not browned, about 5 minutes. Add the mushrooms and season with salt and pepper. Cook mushrooms until they have released their moisture and it has evaporated, about 8-10 minutes.
Add the marsala wine and cook, stirring occasionally until all the liquid has evaporated, about 10 minutes. Add the chicken or vegetable stock and cook, stirring occasionally, until all the liquid has evaporated, about 15-20 minutes. Add the fresh basil and adjust seasonings as needed. Serve with polenta or as desired.
For the polenta:
While the mushrooms are cooking, prepare the polenta. Bring the water to a boil and add the salt. Slowly add the cornmeal/polenta to the boiling water while whisking constantly. Stir in the heavy cream. Return to a boil and then simmer until polenta is softened, about 15 minutes.
Stir in the ricotta cheese, parmesan and butter. Adjust seasoning if necessary and serve immediately. Polenta will solidify as it cools, rewarm to make soft again.
Note: use an assortment of mushroom as you like - oyster, shiitake, portobello, cremini, etc. I recommend not using white button mushrooms as they have little flavor and their high water content will water down the dish.
Calories: 773kcal, Carbohydrates: 46g, Protein: 22g, Fat: 50g, Saturated Fat: 24g, Cholesterol: 117mg, Sodium: 2294mg, Potassium: 725mg, Fiber: 2g, Sugar: 11g, Vitamin A: 1343IU, Vitamin C: 5mg, Calcium: 319mg, Iron: 2mg