Preheat oven to 350°F. Spray a 2-quart baking dish with nonstick cooking spray and set aside.
In a large bowl, combine ground beef, uncooked rice, egg, onion, parsley, salt, and pepper. Shape into 1-inch balls.
Place the meatballs in the prepared baking dish.
In a small bowl, whisk together tomato soup and water. Pour soup mixture over the meatballs.
Cover and bake for 30 minutes.
Remove cover and continue baking for 30 more minutes. At this point, the meatballs should be cooked through and the rice inside the meatballs should be tender. If the rice is still crunchy, cover loosely with foil and return to the oven for another 5-10 minutes (or until rice is done).
Notes
There is not a lot of sauce in the pan with these meatballs. If you prefer a "saucier" dish, use two cans of soup (and twice as much water). Alternatively, add a jar of marinara sauce to the pan with the tomato soup mixture.
I like93% lean ground beef, which is a nice balance of fat to keep the meatballs juicy without leaving too much grease in the baking dish.
This recipe is designed for and tested with long grain white rice. Brown rice, instant rice, and other varieties of rice will require very different cooking times, so they are not equal substitutes.
Combine the meatball mixture with your handsor with a fork -- not with a wooden spoon. The more gentle you can be, the more light and tender your meatballs will stay. Don't overmix, or you'll end up with tough, dense, and dry meatballs.
A cookie dough scoop helps form even meatballs that cook in about the same amount of time. Scoop, roll gently in your hands, and then bake.
In lieu of the ground beef, substitute with ground turkey, ground chicken, ground pork, Italian sausage, or a "meatloaf mixture" (a combination of ground beef, pork, and veal).
Add a couple teaspoons Worcestershire sauce to the meatball mixture for a bit of salty, umami flavor.
Add more flavor with more herbs. Use fresh herbs when available, and include any of your favorites. Basil would also be a nice addition! A teaspoon garlic powder or grated garlic cloves are also great here.
Include some crushed red pepper flakes for spicy meatballs.
Double the Recipe. Using 1 lb. of meat yields about 18 meatballs. If you'd like to prepare a larger batch to feed a group or to save leftovers in the freezer for another meal, just double all of the ingredients. Bake the meatballs in a 13 x 9-inch baking dish.