Pre-heat the oven to 350°Toss the cherry tomatoes with olive oil and season with salt and freshly ground black pepper. Place them on a baking sheet and roast for 20 minutes, stirring halfway through the cooking time. Remove the tomatoes from oven and set aside.

Cut the cauliflower into bite-sized florets. Bring a large pot of salted water to a boil. Blanch the cauliflower in the boiling water for 10 minutes. Drain and set aside.

Combine the butter and cream in a skillet over low heat. Bring the two to a simmer and continue to simmer gently for 10 minutes. Stir in 1¼ cups of the Parmigiano-Reggiano cheese and continue to simmer for another minute or two, until the sauce has thickened. Season to taste with freshly ground black pepper.

Place the blanched cauliflower and the roasted tomatoes in a greased 4-quart. baking dish. Pour the alfredo sauce over the vegetables evenly and top with the remaining Parmesan cheese. Tear the prosciutto into large pieces and tuck them into the cauliflower. Top with freshly ground black pepper and transfer the baking dish to the oven.

Bake at 350°F for 30 to 40 minutes, until the top is golden brown and the prosciutto is crispy. Sprinkle the chopped parsley on top and serve immediately.