In a small mixing bowl, combine the milk and breadcrumb, stir to moisten all the crumbs, and let stand for 10 minutes.
In another small mixing bowl, lightly beat the egg.
In a large mixing bowl, combine the meat, the beaten egg, breadcrumb and milk mixture, salt and pepper, and parsley. Mix the ingredients well.
Add warm water to a small mixing bowl and place it near the stove.
Dip your fingertips into the water and moisten the palm of the other hand. Using the hand with the moistened fingers, scoop out some meat and roll it in your moistened palm using your wet fingers. Drop the meatball into the hot tomato and repeat for the remainder of the meat. The size of the meatball depends on how much you scoop. To be precise, you can pre-measure the meatballs to a specific size. I make 4-ounce meatballs. I weigh them and lay them out onto a pan in rough shapes. I finish the rolling using the wet palm technique and then drop them into the poaching bath.
Cover and cook over medium-low heat for about 30 minutes - to set the meatballs. Then, gently stir the gravy, move the meatballs around, and check to see if the gravy is sticking to the bottom. You don't want scorched gravy on the bottom. Lower the heat if necessary and stir every 30 minutes. I like to cook my gravy for at least several hours.