Season the meat with salt and pepper. In a casserole, heat the oil and sear
the meat, a few pieces at a time, removing them from the pan when they are
brown. Deglaze the pan with the red wine. Next add the lamb with the beef
broth, onions, celery and herbs. Cover and cook in a 300-degree oven for 2
Remove from the oven and discard the large pieces of onion, celery and
herbs. Shred the meat. Strain the broth, return to the casserole, and bring
to a boil.
Slowly whisk the cornstarch mixture into the boiling liquid and stir until
it thickens. Add the lamb, carrots and peas. Transfer to an ovenproof dish
and top with a layer of mashed potatoes. Return to the oven for 15 minutes
or until the liquid is boiling and the potatoes are crisp and brown. You
may have to put the potatoes under the broiler to brown them.