Herb Stuffed Leg of Lamb with Pimento Sauce

Name: Herb Stuffed Leg of Lamb with Pimento Sauce
Ingredients: 1 (6 pound) boneless leg of lamb, with shank; Salt and freshly ground black pepper to taste; 3 tablespoons pureed garlic; 2 tablespoons chopped chipotles (canned); 1/2 cup chopped fresh oregano; 2 tablespoons olive oil; Pimento Sauce (recipe follows); 5 shallots, finely sliced; 1/2 cup mushrooms, sliced; 3/4 cup dry white wine; 5 cups lamb stock or beef broth; 1 teaspoon tomato paste; 3 tablespoons pimento or roasted red pepper pureed in a blender; 1 teaspoon pureed garlic; 1 tablespoon unsalted butter, cold; Salt and freshly ground pepper to taste