This is pure comfort food! You can vary the meat in the shepherd’s pie and use ground lamb, veal or beef.
Sweet Potato Topping
Preheat oven to 375 degrees F.
Line a roasting pan with foil or parchment paper. Add both sweet potatoes and Yukon gold potatoes. Rub potatoes with a little olive oil. Season with allspice, salt and pepper. Bake at 375 degrees. F until potatoes are fork tender, about 50 minutes to 1 hour. Remove from oven. Peel potatoes and add to a large bowl. Mash gently with potato masher. Add butter, cream, nutmeg, and salt and pepper. Stir with wooden spoon until blended. Adjust seasoning.
While the potatoes are roasting, add butter to a large deep skillet over medium heat. Sauté the pork, turkey, shallots and garlic until meat is golden, about 5 to 10 minutes. Add the celery, carrots and cinnamon and cloves. Continue to sauté over high heat until carrots begin to soften, about 5 minutes.
Add white wine to deglaze pan, cook for 2 minutes. Add the Worcestershire sauce, Dijon mustard, thyme, savoury and rosemary and stock. Bring to a boil. Reduce heat to low. Season the mixture with salt and pepper. Simmer covered until meat is tender and moisture is absorbed, about 20 minutes. Remove from heat and set aside.
Add peas to meat filling and transfer to a medium rectangular baking dish (about 7 ½-inches x 11 ½-inches and at least 3-inches deep). Spoon dollops of the sweet potato mixture on top of the meat filling. Spread mixture with a spatula to completely cover meat. Bake until top is golden and meat filling is bubbling, about 25 to 30 minutes.