Normandy Onion Soup (Soupe a L’oignon a la Normande)

Name: Normandy Onion Soup (Soupe a L’oignon a la Normande)
Cuisine: European, Mediterranean, French
Ingredients: 5 tbsp. unsalted butter; 2 medium yellow onions, thinly sliced; 2 Italian parsley sprigs; 2 fresh thyme sprigs; 1 bay leaf; 1 rosemary sprig; 1 cup dry, Norman-style hard cider, divided; 1⁄4 cup all-purpose flour; 2 3⁄4 cups chicken stock; Kosher salt and freshly ground black pepper; oz. Four ½-inch baguette slices, cut on the diagonal; 2 oz. coarsely grated Gruyère cheese (1/3 cup); 1⁄4 cup heavy cream