Clean, trim, and slice the mushrooms.

Use a very large skillet and melt the butter over medium high heat. Once melted, turn the heat to medium-low and add the shallot and onion, stirring until they are coated. Cook for a few minutes.

Next, turn the heat to medium and add the mushrooms, salt, pepper, and rosemary. The mushrooms will absorb the liquid then release some liquid.

Cook the mushrooms for about 5-7 minutes, then turn to medium high and add the garlic, tomato paste, and marsala. Once the marsala is almost absorbed, add the stock. Cook and reduce until the liquid has thickened (approximately 45 minutes).

To finish, stir in the Parmesan and parsley and taste for seasoning. The ragù can be kept warm if it is finished before the polenta.

While the mushrooms cook, make the polenta.

Bring the stock to a boil in a large saucepan. Carefully and slowly stir in the polenta and salt and bring back to a boil. Reduce the heat to low and cook the polenta, stirring often so it doesn’t stick to the bottom. If it gets too thick, add some more warm stock or warm water (¼ cup at a time) to thin it out. Cook until the polenta is soft, and the grains are at the doneness you prefer (approximately 20-30 minutes).

Once cooked, stir in the butter, milk, Parmesan, and pepper. Cook for a few minutes to incorporate everything and check for seasoning. Serve, topped with the mushroom ragù and fresh chopped parsley for garnish.