1.Bring a large pot of salted water to a boil over high heat. Add the pasta and cook until tender but still firm to the bite, stirring occasionally, about 8 to 10 minutes. Drain
2.Preheat oven to 190 degrees C.
3.Meanwhile, in a large skillet warm the olive oil over high heat. Add the onions and the garlic and cook until tender, about 3 minutes. Add the ground lamb, salt, and pepper. Cook until the lamb has browned and the juices have evaporated.
4.Add the red pasta sauce and simmer over low heat until the flavors have blended, about 10 minutes. Mix in the mint.
5.Put the pasta in an oven proof baking dish, sprinkle the mozzarella cheese on top and place in the oven for 10 minutes until the cheese melts and browns. Serve immediately.