Spread the flour about 1/4 inch deep in the center of a baking sheet.
Making the Turkey Meatballs: Pour the olive oil in a medium skillet, drop in the minced onions, sprinkle with a pinch of salt, and set over medium-high heat, stirring until they begin to sizzle. Lower the heat and cook for 4 to 5 minutes, stirring occasionally, until the onions are wilted and slightly dry (but not colored). Scrape them out of the pan and let cool.
Break up the dry bread slices into pieces, roughly an inch or two across — you should have almost 4 cups — and put them in a shallow bowl or baking dish. Pour enough milk over to cover them and soak for 4 to 5 minutes. When the pieces are completely soft, gather them in your hands and firmly squeeze out all the milk; you should have almost a cup of densely packed moist bread. (Give the milk to your cat.)
Forming, Flouring, and Frying Meatballs: Pour vegetable oil into a large, heavy skillet or sauté pan — (12-inch diameter if possible) — to a depth of at least 1/3-inch.
Scoop up a portion of meat with a small ice cream scoop, a large spoon or your fingers. Lightly shape the meat between your palms into 2-inch balls, a bit larger than golf balls (or whatever size you like). Drop the ball onto the floured sheet, roll it around until coated, then place it on another baking sheet. Form and flour all the meat into balls in this manner.
Set the skillet over high heat until the oil is very hot. With tongs or a spatula, carefully transfer meatballs to the pan, as many as you can, leaving at least an inch or so between them. Cook for a minute or two, until they’ve started to brown on the bottom, then turn them continuously — watch out for oil spatters — until golden crusted on all sides, about 6 minutes. As they are done, transfer the fried balls onto a baking sheet. When all the meatballs are on the tray, sprinkle salt lightly over them (just a couple of pinches, in all).
Note: The meatballs will finish cooking in the sauce; they are fried just until a golden crust forms. So if you intend, instead, to eat them as is, be sure to fry them longer until they are cooked through.
Before frying the next batch, turn off the heat and, with a fine-meshed skimmer or strainer, remove any browned bits from the oil. Add oil, if needed, to restore the 1/3-inch depth and heat it up again. When all the meatballs are fried, cook them with a sugo (sauce.)
