Place the torn bread in a small bowl and pour the milk over it; set aside to soak.
Place a roasting pan on the counter; add a healthy drizzle of oil, about 1 tablespoon.
Add the canned tomatoes to the pan and crush with a potato masher or a wooden spoon.
Season the tomatoes liberally with salt and pepper.
In a large bowl, using your hands, combine the ground sirloin, the remaining tablespoon oil, the garlic, parsley, oregano, red pepper flakes, allspice, Parmigiano-Reggiano, pine nuts, currants, egg, and salt and pepper.
Squeeze out the excess milk from the soaking bread (it should be loose and in small pieces), then add it to the meat mixture; discard the milk.
Form the meatball mixture into 12 baseball-size balls, each about 3 inches in diameter, and place them in the roasting pan, nestling them into the tomatoes.
Roast until the meatballs are brown and cooked through, about 30 minutes.
Place the ciabatta, unwrapped, in the oven to heat when the meatballs are just about done.
Tear the warm, crusty bread into large pieces.
Remove the meatballs from the oven and arrange the torn pieces of bread in and around the meatballs and sauce.
Stir the ricotta cheese together with the basil, season with salt and pepper, and pass at the table.
Complement each serving of 2 large meatballs with 2-3 tablespoons of cool ricotta spooned along side.