Brown the lamb shanks: In a large, heavy pot or Dutch oven, heat the olive oil over medium-high heat. Season the lamb shanks with salt and pepper, then brown them on all sides, about 4-5 minutes per side. Remove the lamb from the pot and set aside.

Sauté the onions and garlic: In the same pot, add the chopped onion and garlic. Sauté until softened and fragrant, about 5 minutes.

Deglaze with whiskey: Pour the Irish whiskey into the pot to deglaze, scraping up any brown bits from the bottom. Allow the whiskey to cook down for about 2 minutes.

Add broth and tomato paste: Stir in the beef broth and tomato paste. Return the lamb shanks to the pot and add the fresh rosemary and thyme.

Simmer and cook: Cover the pot and simmer on low heat for 2-2.5 hours, turning the lamb shanks occasionally, until the meat is tender and falling off the bone.

Finish with cream: Stir in the heavy cream and let the sauce thicken for about 5 minutes. Adjust seasoning with salt and pepper.

Serve: Serve the lamb shanks with a generous spoonful of the whiskey sauce and garnish with fresh parsley.