It's St. Patrick's Day and the Irish-Americans are smiling, parading and doing (ahem) other things today, so Funny or Die corralled famous Irish-American comedian Denis Leary to explain the secrets of a favorite Irish dish: Shepherd's Pie. It's as if he told you what really goes into a hot dog was dog. How. Dare. He. I refuse to believe any of this is true. You be the judge!