In a large pot bring water/stock to boil with a generous pinch of salt.
Once water is boiling, slowly pour in polenta whisking continuously to prevent any lumps.
Reduce heat to low and continue to whisk until polenta is thick and starts to come off the sides of the pot. Check directions on the package for approximate cooking time. Different kinds of polenta cook anywhere between 5 and 40 minutes.
Once polenta is cooked, add butter and grated Parmesan cheese. Mix well.
Lightly oil or line with a parchment paper 13x9 inch baking pan.
While polenta is still hot spread it evenly in the baking pan.
Let cool.
In the meantime prepare mushrooms.
Prepare Mushroom Ragu
If you got a pack of already sliced mushroom, skip step 1 entirely and start from step 2.
Briefly clean the mushrooms under the running cold water, dry gently with a paper towel. Remove most dirty and external parts of the stem.Depending on the type of mushrooms slice them lengthwise.
Place a large skillet pan over medium heat.
Add olive oil, butter, chili flakes, chopped parsley and garlic cloves crushed with a flat knife or minced if you like more pronounced garlic flavor. Saute for a minute or two.
Add sliced mushrooms and stir everything together. Mushrooms will release liquid. Continue cooking for another 5-6 minutes until all the linquid is gone.
Add heavy cream and simmer for another few minutes until creamy. Add some cheese if you like.
Assemble Polenta Squares
Once polenta is completely cool cut it into bite size squares.
Arrange polenta squares ½ inch apart on a clean baking pan line with parchment paper.
Top each square with mushroom ragu and grated Asiago cheese.
Bake in a preheated to 375/ 190 oven for 5-10 minutes until cheese is melted.