Grease a casserole dish with 1 tablespoon of the butter and set aside.
Position rack in center of oven and preheat the oven to 375°F.
In a medium saucepan, place the potatoes and 1 teaspoon of the salt. Cover with water by 1 inch and bring to a boil over high heat.
Reduce the heat and cook at a low boil until fork-tender, about 12 to 15 minutes.
Using oven mitts or pot holders, drain potatoes in a colander set in the sink and then return them to the saucepan. Add the remaining 4 tablespoons of butter, the milk, heavy cream, 1/2 teaspoon of the salt, and 1/8 teaspoon of the black pepper. Mash with a potato masher until smooth. Set aside.
In a large skillet, heat the vegetable oil over medium-high heat. Add the onion and cook, stirring, until soft, about 3 minutes.
Add the garlic and cook, stirring, for 30 seconds, then add the ground lamb or beef and cook, stirring to break up the meat chunks, until cooked though, about 8 minutes.
Remove the pan from the heat. Tilt the pan slightly away from you, and with a tablespoon carefully remove as much excess liquid as possible from the pan into a bowl. Discard the liquid.
Return the skillet to medium-high heat. Add the Italian Essence, thyme, the remaining 1/2 teaspoon of salt, the remaining 1/4 teaspoon of black pepper, the cinnamon, and cloves, and cook until the meat is well browned, stirring frequently, about 6 to 8 minutes.
Sprinkle the meat with the flour and cook, stirring, for about 1 to 2 minutes.
Add the beef broth, carrots, peas, and tomato paste, stir to combine, and bring to a boil.
Reduce the heat to medium-low and simmer until thickened, about 5 to 6 minutes.
Transfer the mixture to the prepared casserole dish and spoon the mashed potatoes evenly over the top. Sprinkle with the cheese and bake for 30 minutes.
Increase the oven temperature to broil and cook until golden brown and crisp around the edges, about 4 to 6 minutes.
Using oven mitts or pot holders, remove the casserole from the oven and let it sit for 10 minutes before serving. This pan will be very hot, so be very, very careful!
YIELD: 6 servings