Preheat oven to 350
Wash the tomatoes. Turn the stem side down and cut the bottom of the tomato, being careful not to disconnect the cap. With a small spoon, carefully scoop out and reserve the pulp. Place cored tomatoes in a high-sided baking dish.
Meanwhile, heat the oil in a heavy skillet. Add onions and cook on moderate heat until soft and transparent. Add garlic and parsley, stirring to combine. Once the garlic is fragrant, add meat, mashing with a fork or wooden spoon, and cook until lightly browned. Add wine and water, then cover and cook for a few minutes. Stir in the rice and tomato pulp; there should be enough liquid for the rice to cook, but add tomato juice or additional water if needed. Season with salt, pepper, mint, and nutmeg, then remove filling from heat.
Partially fill tomatoes with stuffing, including cooking liquid. Cover with caps and bake for 1 hour or until rice is tender. Serve warm.