Heat the oven to 180C/fan 160C/gas 4. Arrange the tomatoes on a baking tray and season. Bake for 20 minutes, remove from oven and set aside. Reduce the heat to 120C/fan 100C/gas 1/2.
Put one scallop on each piece of prosciutto, roll up tightly and secure with a toothpick. Heat a frying pan until very hot. Add the olive oil and sear the scallops until the prosciutto is browned and crisp on both sides. Keep warm in the oven while searing the rest.
Add the butter and garlic to the pan and cook for 2 minutes on a low heat. Add the lemon rind and juice and heat through. Add the parsley. Serve the scallops with the tomatoes and the garlic butter drizzled over.