With the rack in the highest position, preheat the oven’s broiler. Line two baking sheets with foil. Set aside.
In a large bowl, combine the bread and milk. Let soak for 5 minutes.
In a food processor, finely chop the carrot and leek. Add to the bowl of soaked bread. Season with salt and pepper. Add the remaining ingredients and combine with your hands.
With a small ice cream scoop and lightly oiled hands, shape about 4 dozen small meatballs using 1 tbsp of the meat mixture for each. Place on the prepared baking sheets, spacing them out evenly.
Bake one sheet of meatballs for 5 minutes. Remove from the oven, turn the meatballs and continue baking for 5 minutes or until cooked through and golden brown. Repeat with the remaining sheet of meatballs.