A head of garlic. Peel, stem removed. Garlic will give it flavor. Add fresh pepper, nonfat milk, nonfat yogurt. Place on top of the lamb, onions that have been braised.
Fresh herbs work great as well.
This is a delicious dish. This is the first time I have been asked this question, so this is how I would make it. These are very expensive. The white ones are very expensive. If you're using real truffles, you won't get a lot a flavor for the price.