Mushroom Bolognese

Name: Mushroom Bolognese
Ingredients: 1 small onion, coarsely chopped; 1 medium carrot, coarsely chopped; 1 celery rib, coarsely chopped; 1 medium parsnip, chopped; 1/2 small turnip, coarsely chopped; 1 pound king oyster mushrooms; 1/4 cup extra-virgin olive oil; Kosher salt; Ground pepper; 1 ounce dried porcini mushrooms; 1/2 cup dry red wine; 1 small Parmigiano-Reggiano cheese rind, plus 1/4 cup freshly grated Parmigiano-Reggiano; Pinch of crushed red pepper; 1/4 cup heavy cream; 1 teaspoon minced rosemary; 1 1/2 pounds spaghetti, cooked until al dente and kept warm; 4 tablespoons unsalted butter