Preheat the oven to 350°F.
In a large bowl, combine all the ingredients for the meatballs, except the oil and butter. Mix well with your hands. Form into mini-sized meatballs, about 1-inch in diameter.
In a medium skillet, heat 1 teaspoon of the oil and 1 teaspoon of the butter over medium-high heat. Add half of the meatballs and cook, turning until brown on all sides, about 4 minutes. Transfer to a 2 1/2-quart baking dish. Add the remaining teaspoon of oil and butter to the skillet and cook the remaining meatballs.
Make the sauce by combining all the ingredients in a medium bowl, whisking to dissolve the sugar and blend. Adjust the seasoning to taste. Pour the sauce over the meatballs and bake until the meat is cooked through and the sauce is bubbly, about 20 minutes. Remove from the oven and serve immediately.