Soft Polenta with Mixed Mushrooms and Gremolata recipes

Name: Soft Polenta with Mixed Mushrooms and Gremolata recipes
Ingredients: 1 1/2 cups medium-grain polenta; kosher salt; 6 tablespoons unsalted butter; freshly ground pepper; 1/2 cup chopped flat-leaf parsley; 1 teaspoon chopped garlic; 1 tablespoon finely grated lemon zest; 1/4 cup extra-virgin olive oil; 1 1/2 pounds mixed mushrooms, such as cremini, oyster and stemmed shiitake, thickly sliced or quartered; 4 ounces young greens, such as spinach, Russian kale or pea shoots, coarsely chopped (4 cups packed); 1/2 cup mascarpone cheese