Butterfly it, marinate in red wine, mustard, pepper, garlic, and oregano for at least 3 hrs. Pat dry, season with salt and pepper then grill...Serve with quinoa spinach feta and pine nuts.

Braise the leg of lamb until tender and meat is falling off. Best served with a side or Orzo in tomato sauce...

I like to serve it with traditional cannelini beans cooked in some good stock (chicken or vegetable), with onion and garlic and also a fair amount of good olive oil and some fresh rosemary.

The user contributed recipes here on food52.com are pretty good. Here is a contest winner from last year--Leg of Lamb with Garlic Sauce. I'd want to serve it with a pile of roasted small potatoes and roasted asparagus.
V=http://www.food52.com/recipes/3814_leg_of_lamb_with_garlic_sauce

You would have to grind it but the Lebanese dish called "Kibbe" would be a great dish that your dinner guests might not be familiar with. Your side dishes could be tabbouleh, hummus, babba ganoush, stuffed grape leaves, lentil soup, etc... All the side dishes could be made ahead of time.