Ingredients
1 ounce dried porcini mushrooms, rinsed under cold water
2 tablespoons olive oil
1 small onion, finely chopped
2 garlic cloves, minced
1 1/2 pounds small white button mushrooms, halved
Coarse salt and ground pepper
1/2 teaspoon dried thyme
1/2 cup dry sherry or red wine
1 tablespoon tomato paste
1 teaspoon balsamic vinegar
1 cup yellow cornmeal
4 1/4 cup cold water
2 teaspoons coarse salt
1/8 teaspoon ground pepper
1 cup grated Fontina cheese
2 tablespoons butter
Preparation
Place dried mushrooms in a medium bowl; add 4 cups warm water. Let soak until soft, about 30 minutes. Drain in a sieve lined with a paper towel or coffee filter, reserving liquid. Squeeze mushrooms to remove excess liquid; roughly chop.
In a 12-inch skillet, heat oil over medium heat. Cook onion, stirring often, until soft, about 5 minutes. Add garlic; cook until fragrant, about 30 seconds. Add fresh mushrooms; season with salt and pepper. Cover; cook until mushrooms release their juices, about 10 minutes. (If mushrooms begin to brown, add up to 1/4 cup water.)
Uncover; raise heat to high. Cook, stirring often, until liquid evaporates and mushrooms brown, 5 to 6 minutes. Add dried mushrooms, thyme, sherry, and tomato paste; cook until pan is dry, about 2 minutes. Stir in reserved liquid. Simmer, partially covered, until sauce has thickened, about 25 minutes. Stir in vinegar. Serve over soft polenta (see below).
To make soft polenta: In a small bowl, whisk together the yellow cornmeal with 1 cup cold water. In a medium saucepan, bring the remaining 3 1/4 cups water, coarse salt, and ground pepper to a fill rapid boil. Gradually stir in cornmeal mixture. Simmer, stirring frequently, until mixture is thick, 8 to 10 minutes. Remove from heat; stir in grated Fontina cheese and butter until melted.
