Cook the rice by simmering it in broth with salt until liquid is absorbed. Fluff and set aside.In a skillet, heat oil and sauté onions until golden. Add carrots and cook for 5 to 10 more minutes. Stir in tomatoes and garlic, cover, and cook until softened. Let cool.Wash mini peppers, slice off tops, and remove seeds.In a large bowl, combine the cooked rice, sautéed vegetables, raw ground beef, parsley, salt, pepper, garlic, and smoked paprika.Stuff the hollowed mini peppers tightly with the beef-rice mixture. Arrange snugly in a 9x12-inch baking dish.Pour hot seasoned broth into the dish around the peppers, filling halfway up the sides. Cover with foil and bake at 350°F for 45 minutes.Uncover, sprinkle mozzarella cheese on top, and bake an additional 5 to 10 minutes until the cheese is melted.For optional sauce, sauté onion and carrot, then add tomatoes, garlic, and wine. Cook until softened. Stir in sour cream, simmer to thicken, and season to taste.Serve stuffed peppers topped with creamy tomato sauce or sour cream and a sprinkle of parsley.