1Grab the largest sheet pan you have and add all the potatoes and meatballs in it.
2Peel the potatoes ahead of time, pour water on them, and tuck them in the fridge.
3Cut the peeled potatoes into chunks.
4Spread the potatoes in the sheet pan and add the sliced red onions.
5Add kosher salt and black pepper to the potatoes and onions.
6In a large bowl, combine the ground beef, soaked bread, egg, grated yellow onion, minced garlic, parsley, Greek oregano, ground coriander, ground cumin, salt, pepper and Greek extra virgin olive oil.
7Mix the meatball ingredients with your hands (gloves on).
8Form the mixture into meatballs and arrange them on top of the potatoes and onions in the sheet pan.
9In a measuring cup, whisk together the fresh lemon juice, minced garlic, salt, pepper, Greek oregano, and Greek extra virgin olive oil to make the lemon sauce.
10Pour the lemon sauce over the meatballs and potatoes.
11Cover with foil and bake at 375°F for 30-40 minutes.
12Uncover and bake for another 10-15 minutes to crisp up the potatoes and brown the meatballs.