Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Place lamb, boned side up on a flat surface and sprinkle with salt, pepper, and, 1 teaspoon cumin.  Roll up jelly roll-style and tie with string.  Sprinkle with salt and pepper.  If desired, dredge in flour.

Heat two tablespoons oil in a large pot or roasting pan over medium heat.  Brown lamb on all sides (15–20 minutes).  Remove lamb and pour off excess fat.

Add remaining two tablespoons oil and sauté onions, carrot celery, and garlic until softened (about 10 minutes).  Add remaining one teaspoon cumin and tomato paste and stir until darkened.  Stir in rosemary.

Add wine, stirring to remove any browned particles and bring to a boil.  Return lamb, add broth, and bring to a simmer.

Cover, place in oven, and cook, basting occasionally, until tender about 25–35 minutes per pound or until thermometer registers 145 degrees Fahrenheit for rare (about two hours) or 150 degrees for medium (two to two and a half hours).  Serve with couscous.