Roast Lamb with Lamb Sausage Crust and Fresh Grape Pan Sauce

Name: Roast Lamb with Lamb Sausage Crust and Fresh Grape Pan Sauce
Ingredients: 2 cups halved seedless red grapes; 2 cups tawny Port; 2 cups low-salt chicken broth; 2 teaspoons chopped fresh rosemary; 1/2 cup halved seedless red grapes; 1/4 cup halved pitted Kalamata olives; 1 tablespoon chopped fresh rosemary; 1 teaspoon balsamic vinegar; 1 small garlic clove; 8 ounces ground lamb; 1/2 teaspoon coarse kosher salt; 1/4 teaspoon freshly ground black pepper; 2 2- to 2 1/2-pound well-trimmed racks of lamb (each with 8 bones); 4 tablespoons olive oil, divided; 1/2 cup low-salt chicken broth; 4 tablespoons Dijon mustard, divided; 2 1/2 cups fresh breadcrumbs made from crustless French bread