In a large Dutch oven, heat oil over medium heat.

 

Stir together flour, rosemary, salt, and pepper. Dredge lamb cubes in flour mixture and brown in hot oil, half a batch at a time. Remove meat and add onions, carrots, and celery to skillet drippings. Sauté 3-5 minutes or until onion is translucent and golden. Return meat and add potatoes and stock.

 

Reduce heat, cover, and simmer 2-1/2 hours, or until lamb is tender. Stir-in cornstarch mixture, parsley, and thyme and cook, uncovered, 3-5 minutes or until thickened.