Porcini Rack of Lamb

Name: Porcini Rack of Lamb
Ingredients: 3 large unpeeled shallots; 1 ½ teaspoons olive oil; 1 ¼ cups port; 2 tablespoons butter; 2 teaspoons very thinly sliced garlic; 3 tablespoons all-purpose flour; 1 (14 ounce) can reduced-sodium chicken broth; ¼ cup prepared demi-glace (see Tip); 1 teaspoon reduced-sodium soy sauce; ⅛ teaspoon freshly ground black pepper; 1 ounce dried porcini mushrooms (1 cup); 1 ½ teaspoons freshly ground black pepper; ¾ teaspoon salt; 3 (1 to 1 1/4 pound) racks of lamb, trimmed