Recipe: Polenta Casserole with Sauteed Mushrooms, Blue Cheese, and Walnuts

POLENTA CASSEROLE WITH SAUTEED MUSHROOMS,
BLUE CHEESE, AND WALNUTS

FOR THE POLENTA:
2 1/2 cups whole milk
3 cups water
Salt
1 1/2 cups instant polenta
2 tablespoons unsalted butter
1 medium garlic clove, minced or pressed through a garlic press
Ground black pepper
FOR THE TOPPING:
1/4 cup olive oil
12 ounces portobello mushroom caps (about 8 medium caps), brushed clean and sliced 1/4-inch thick
1 1/4 pounds white button mushrooms, stems discarded, brushed clean, and sliced 1/4-inch thick
1 large red onion, halved and sliced thin
Salt
6 medium garlic cloves, minced or pressed through a garlic press
1 tablespoon minced fresh thyme leaves
1/4 ounce dried porcini mushrooms, rinsed and rehydrated, with soaking liquid reserved
5 ounces Gorgonzola cheese, crumbled (about 1 1/4 cups)
3/4 cup walnuts, coarsely chopped
2 tablespoons minced fresh parsley leaves

Adjust oven rack to middle position and heat oven to 400 degrees F.

TO MAKE POLENTA:
Bring milk, water and 2 teaspoons salt to simmer in large, heavy-bottomed saucepan over medium-high heat. Very slowly, pour polenta into boiling liquid while stirring constantly in circular motion with wooden spoon. Reduce heat to lowest setting and cover. Cook, vigorously stirring polenta every few minutes, making sure to scrape clean bottom and edges of pot, until polenta has lost its raw cornmeal taste and become soft and smooth, about 10 minutes.

Off heat, stir in butter and garlic. Season to taste with salt and pepper; cover pot to keep polenta from drying out and set aside.

TO MAKE TOPPING:
Heat oil in a Dutch oven over high heat until shimmering. Add portobellos, white button mushrooms, onion and 1/2 teaspoon salt; cook, stirring often, until mushrooms have released their liquid, shrunk dramatically and browned, about 20 minutes.

Add garlic, thyme and dried porcini mushrooms with their reserved liquid (be careful not to add any sediment to the pot); cook until most liquid has evaporated, about 2 minutes. Season to taste with salt and pepper.

Spread cooked polenta into bottom of 9-by-13-inch baking dish. Spread mushrooms evenly over polenta and sprinkle with Gorgonzola and walnuts.

Bake until polenta has heated through and walnuts have toasted, about 20 minutes. Cool for 10 minutes. Sprinkle with parsley before serving.

TO MAKE AHEAD:
Casserole can be assembled ahead of time and not baked until later. Wrap dish tightly with plastic wrap and poke vent holes with tip of paring knife. Refrigerate until cool, about 2 hours, then wrap tightly with another sheet of plastic wrap and refrigerate up to 2 days. Bring to room temperature; remove plastic wrap and cover casserole with foil. Bake until heated through, about 1 hour. Cool 10 minutes before serving.

Servings: 6
Source: Cover & Bake by Editors of Cook's Illustrated magazine