On a large cutting surface, lay out lamb, cut side up so that it folds open. Sprinkle the inside with salt and Essence. Place a rosemary stalk inside. Tie lamb up with another rosemary stalk so that it is rolled and secure. Season the outside of the lamb with more salt, and the coriander and cumin.
In large saute pan over high heat, add olive oil and heat until hot, but not smoking. Add lamb and sear, on all sides until golden brown, about 5 minutes, being careful not to let the rosemary burn. Transfer to oven and continue cooking for another 20 minutes, or until medium rare. Remove from oven and set aside for 10 minutes while preparing couscous.
Slice into 1-inch pieces. Serve atop couscous.
Emeril's ESSENCE Creole Seasoning (also referred to as Bayou Blast):
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch, published by William Morrow, 1993.
In a large bowl, combine the couscous and salt. Pour the boiling water over the mixture, cover, and let stand until the water is absorbed and the couscous is puffed, about 6 minutes. Uncover and fluff with a fork. Add the pistachios, mint, and oil. Adjust seasoning, to taste. Serve hot.