1. Thoroughly mix all marinade ingredients in a bowl.
2. Pour marinade into a large zippered bag and add lamb steaks. Toss to coat thoroughly and refrigerate for 8 - 24 hours, Tossing every now and then to redistribute marinade.
3. Heat oven to 225 degrees.
4. Remove steaks from bag, discarding marinade, and wipe dry (more or less) with paper towels. Heat 2 Tbsp. olive oil in a large, lidded sauté pan over medium-high heat. Brown steaks on both sides in pan (about 3 minutes per side).
5. Pour off excess oil, cover sauté pan, and cook in the oven for 1 hour.
6. In the meantime, combine sauce ingredients in a small bowl.
7. Remove from pan and slice steaks thinly across the grain.
8. Spoon sauce down the center of a loaf of flat bread or pita. Add tomato and a leaf or two of lettuce. Add lamb, roll up, and enjoy.