Low Country Shrimp and Grits with Stewed Tomatoes

Name: Low Country Shrimp and Grits with Stewed Tomatoes
Ingredients: 2 cups 2-percent milk; Coarse kosher salt and freshly ground black pepper; 1 cup stone-ground grits; 1 tablespoon olive oil; 1 medium onion, coarsely chopped; 3 cloves garlic, finely chopped; One 28-ounce can low-sodium whole tomatoes, coarsely chopped, juice reserved; 2 bay leaves, preferably fresh; 1 pinch ground cayenne pepper or to taste; 24 large fresh shrimp, peeled and deveined (tails left on); 2 tablespoons chopped fresh parsley, plus more for garnish; 2 tablespoons freshly grated Parmigiano-Reggiano, plus more for garnish; 1 tablespoon unsalted butter