1. 4 cups water
2. 1 cup polenta
3. 1/2 cup finely grated Parmesan cheese
4. 3/4 teaspoon kosher salt, divided
5. 2 tablespoons olive oil
6. 1 small yellow onion, diced
7. 3 cloves garlic, minced
8. 1 pound mixed wild mushrooms, cleaned and sliced
9. 1 pound cremini mushrooms, cleaned and sliced
10. 1 tablespoon minced fresh thyme
11. 2 tablespoons all-purpose flour
12. 1/2 cup dry white wine
13. 1/4 cup heavy cream
14. 1 teaspoon sugar
15. 1 squeeze fresh lemon juice
16. 1/2 cup chopped flat-leaf parsley
1. Bring 4 cups of water to a boil. Whisk in the polenta. Once it begins to thicken, reduce heat to a simmer and cook for 45 minutes until creamy and thick, stirring occasionally to prevent sticking. Stir in the Parmesan and a 1/4 teaspoon of salt. Stir until melted and cheese is no longer visible. Remove from heat.
2. Line an 8x11 inch baking dish with Reynolds Wrap(R) Aluminum Foil and carefully pour the polenta into the baking dish, using a spatula to smooth it to an even thickness, about 3/4 inch. Cover and refrigerate for at least two hours and up to two days until firm.
3. While the polenta chills, make your ragu. In a large heavy skillet, heat the olive oil over medium heat until shimmering. Add the onion and garlic and saute until fragrant and translucent, about 5 minutes. Stir often to prevent browning. Add mushrooms and thyme and cook over medium-high heat until the mushrooms start to release their liquid. Add 1/2 teaspoon of salt and continue to cook another 5 minutes until they begin to soften more.
4. Add flour, stirring, until it is no longer visible, about 1 minute. Add in the wine, cream and sugar, and bring the mixture to a simmer. Taste and adjust salt if desired. Simmer until thick and creamy and the mushrooms are nicely coated, about 15 minutes. Finish with a squeeze of fresh lemon juice and 1/2 cup minced parsley. Set aside and cover to keep warm.
5. Slice your polenta into squares -- whatever size you desire. Wipe down your skillet, coat it with nonstick cooking spray, and heat it over medium-high. Fry the squares in the pan until golden brown and warmed through. To serve, top the squares with warm mushroom ragu.