In a pan, brown the lamb and Italian sausage, then add the rosemary.
Season with salt and pepper, and let it cook on low heat for about 20 minutes.
Stir in the garlic and tomato paste.
Add the blended fresh tomatoes, bay leaves, and pieces of Parmesan cheese.
Cover with a cartouche and continue to cook on low heat for about 3 hours.
In a separate bowl, mix the store-bought mashed potatoes with butter and cheddar cheese, then set aside.
Thicken the meat sauce with a little butter and a splash of vinegar.
Spread the mashed potato mixture over the meat in a pie pan.
Top with fresh thyme leaves and melted butter.
Bake in a preheated oven at 375°F for about 45 minutes, or until the top is golden and bubbling.
Allow the pie to rest for 5–6 minutes, then garnish with finely chopped chives.
