Blend or whisk the ingredients and season with salt and pepper to taste.
For the meatballs
Submerge the bread slices in either milk or water for a few minutes then squeeze out the liquid. Place the bread into a large mixing bowl and break it up with a fork.
Add the beef and lamb to the bowl and season with salt, pepper, and nutmeg.
To the meat, add the parsley, mint, garlic paste, and grated onion. Add the beaten egg and gently mix everything together.
With wet hands roll approximately 2" diameter meatballs and set them on a parchment paper lined baking sheet. Note: It's quicker to get the potatoes cooking and start prepping the meatballs.
For the potatoes
Preheat oven to 425°F and set the rack to the middle level.
Place the potatoes into a 9×13" baking dish and pour half of the ladolemono sauce onto the potatoes. Season with oregano and salt and pepper and mix well to coat. Pour the stock into the baking dish. Bake for 30 minutes.
After 30 minutes, remove the dish from the oven and place the meatballs on top of the potatoes. Turn the heat down to 375°F and return to the oven and bake for another 30 minutes or until the potatoes are tender and the meatballs are cooked through. You can broil for the last 2 minutes if you like but watch carefully. Spoon over a bit of the remaining ladolemono sauce and serve the remainder along with some feta cheese at the table. Enjoy!
Notes
Meat. Chuck, which has a large amount of fat and flavor, and ground lamb are a great combo for juicy tender meatballs. Avoid using really lean meats if at all possible.
Mixing the meatballs. It’s crucial to not over-mix a meatball and to not form them too tightly. Use wet hands and roll the meatballs by hand until there are no cracks.
Leftovers. The Greek meatballs and potatoes can be stored in the fridge for 3 days and can be reheated in the oven or microwave. The ladolemono sauce can be saved in the fridge for up to 5 days.