RE: Grilled Greek-style boneless lamb
Olive oil, parsley, oregano, garlic, salt, black pepper, lemon juice. Proportions to taste, but don't think you need to drown it in oil. Go easy on the lemon or it can get pretty sour.
For a more frencified version, substitute tarragon (again, easy does it) for the oregano and red wine for the lemon (but in greater quantity). Also good with some whole mustard seed.
A little wood smoke adds a nice element as well.