Sausages and Grapes with Cheesy Polenta

Name: Sausages and Grapes with Cheesy Polenta
Ingredients: 2 tablespoons extra-virgin olive oil; 4 sweet Italian sausages (about 4 ounces each); 6 cloves garlic; 1/2 cup dry red wine; 1 1/2 pounds seedless red grapes (5 to 6 cups); 1/2 to 1 teaspoon red wine vinegar; Kosher salt and freshly ground pepper; 4 cups whole milk; 1 cup quick-cooking polenta; 4 sprigs fresh thyme, leaves stripped; 1 cup grated fontina cheese (about 3 ounces); 3 tablespoons chopped fresh parsley, plus more for topping