Lamb Ragout With Olives And Peppers

Name: Lamb Ragout With Olives And Peppers
Ingredients: 1/4 cup canola oil; 4 pounds boneless lamb shoulder, cut into 2-inch chunks; Salt and freshly ground black pepper; 2 large white onions, coarsely chopped; 4 celery ribs, coarsely chopped; 3 carrots, coarsely chopped; 1/4 cup tomato paste; 1 cup dry red wine; 10 cups water; 1 tablespoon unsalted butter, softened; 1 tablespoon all-purpose flour; 3/4 cup sliced pitted Picholine olives; 3/4 cup sliced roasted red peppers; 2 tablespoons chopped tarragon; 2 cups Israeli couscous