In a medium bowl, combine rice and hot water. Let sit for 20 to 25 minutes.
Heat oven to 375°F.
While rice soaks, in a large bowl combine the ground beef, onion,garlic, parsley, pepper, salt and cayenne. When rice has soaked 20 minutes add the rice and the water. Mix until everything is evenly distributed.
Form mixture into 10 meatballs (they will be about ⅓ cup each). Place the meatballs in a 3-qt or 9-by-13-inch baking dish. Set aside while you make the sauce.
Make the sauce & Cook
In a separate bowl combinediced tomatoes and tomato sauce. Stir together the water and flour and add to tomatoes. Stir in onion, garlic, green pepper, and Worcestershire. Add the sugar, celery seed and salt.
Pour the tomato sauce around the meatballs and cover the dish tightly with foil. Bake for 1 hr, then remove the foil and bake until the tops are just browning, 20 to 25 minutes more.
Garnish with chopped parsley if desired and serve.
Meatballs and sauce can be stored in an airtight container in the fridge for up to 3 days. Reheat in a foil-covered dish in a hot oven or in the microwave.GLUTEN-FREE:Make the sauce gluten-free by using GF-all-purpose flour in place of the wheat flour. SALT:Many canned tomato sauces have a great deal of sodium which will make your final dish saltier. If you taste your tomato sauce and find it salty, just reduce the amount of kosher salt called for in the recipe.VEGETARIAN:See the post for a vegetarian and vegan option for this recipe.