New York Strip and Fall Vegetable Roast with Mustard Cream Sauce

Name: New York Strip and Fall Vegetable Roast with Mustard Cream Sauce
Ingredients: 1/2 cup crème fraîche or sour cream; 2 tablespoons Dijon mustard; 1 teaspoon fresh lemon juice; Coarse kosher salt; 1 tablespoon unsalted butter, room temperature; 2 garlic cloves, pressed; 1 teaspoon finely chopped fresh rosemary; 3/4 teaspoon coarse kosher salt; 1/2 teaspoon freshly cracked black pepper; 1 3-pound boneless beef loin New York strip roast; 1 pound assorted mushrooms (such as button, crimini, and oyster), large mushrooms halved; 1 pound turnips (about 2 medium), peeled, cut into 2x1/2x1/2-inch strips; 12 ounces carrots (about 4 medium), peeled, quartered lengthwise, cut crosswise into 1 1/2-to 2-inch pieces; 1 12-ounce celery root (about 1 medium), peeled, cut into 2 x 1/2 x 1/2-inch strips; 5 large shallots (about 12 ounces total), peeled, cut crosswise into 1/4-inch-thick slices; 5 tablespoons extra-virgin olive oil; 1 1/2 tablespoons chopped fresh rosemary