Starring tender braised lamb with pearl onions, peas, rapini and carrots all topped with broiled mashed potatoes, this hearty shepherd's pie is the ultimate comfort food!

Preparation

For the lamb, season shanks with salt and pepper. Heat a 2-gallon stock pot with a lid on medium-high heat. Add vegetable oil and then sear shanks on all sides until well browned. Remove to a plate. 

Add the onion, carrot, celery, garlic, bay leaf, thyme and rosemary to the pan. Sauté until the vegetables begin to caramelize. Add the tomato paste and continue to cook and stir until the paste begins to brown. Deglaze with red wine and reduce to a light syrup. Add the beef stock and bring to a simmer. Add the lamb shanks with any juices collected and return to a simmer. Cover with lid and place in oven. Braise for 2½–3 hours, until meat is just falling off the bone.

Remove lamb shanks from the pot and reserve. Strain the braising liquid through a fine mesh strainer and discard any solids. Place braising liquid into a sauce pot and reduce over medium heat to a volume of 1 quart while skimming away and discarding any grease that rises to the top. Pick all meat from the bones in large shreds and reserve.

For the mashed potatoes, heat oven to 400°F. Bake potatoes 60–80 minutes, or until soft. Remove potatoes from oven and let rest for 5 minutes. Cut potatoes in half, scoop out the flesh and press through a food mill or mash with a potato masher. Add butter and mix thoroughly. Fold in cream, then season with salt and pepper.

For the filling, melt 2 tablespoons butter in a 4-quart sauce pot. Add the flour and cook 1–2 minutes, until golden brown. Whisk in the skimmed braising liquid 1 cup at a time to create a smooth sauce. Bring to a simmer and let simmer for 15 minutes, stirring occasionally.

In large sauté pan, melt remaining butter on medium-low heat and add the pearl onions. Cook for about 10 minutes, until caramelized. Add the carrots and garlic and sauté 5 more minutes, until carrots are caramelized and tender. Add the rapini and sauté for 1 minute. Add the picked lamb meat, peas, thyme and thickened braising liquid and bring to a simmer.

Transfer mixture to a 10-inch pie dish or casserole dish of similar size, leaving about ¾ inch of space at the top. Pipe or spoon hot mashed potatoes onto the surface and gently spread until even.

Heat broiler on high and place shepherd's pie in the oven on the bottom rack. Broil for 7–10 minutes, until potatoes are golden brown and filling is just bubbling. Serve immediately.