6 cups chicken stock, plus more if needed
2 1/2 cups coarse polenta
Salt and coarse black pepper
Salt and coarse black pepper
6 tablespoons butter, plus more for dotting casserole
1/2 cup dried porcini mushrooms (a couple of handfuls)
About 1/3 cup EVOO
1 1/2 pounds cremini or white mushrooms, sliced
2 tablespoons finely chopped fresh thyme
2 shallots, finely chopped
1/2 cup dry white wine or 1/4 cup Marsala or sherry
2 cloves garlic, grated
1/4 cup flour
2 1/2 cups milk
Freshly grated nutmeg, as needed
1 1/2 cups grated Parmigiano-Reggiano