Preheat the oven to 450 degrees. Line a baking sheet with foil and place a cooling rack on top.
In a small measuring cup or bowl, combine the bread crumbs and milk. Allow the crumbs to soak while you prepare the rest of the ingredients.
In a mixing bowl, use your hands to combine the beef, lemon juice, oregano, mint, onion, garlic, eggs, salt, and pepper. Work in the soaked bread crumbs.
Use a cookie scoop to portion the meatballs, then place them on the cooling rack. Bake for 16-20 minutes or until golden brown and cooked through.
While the meatballs bake, whisk together all the ingredients for the sauce.
Serve the meatballs with the yogurt sauce or make pita sandwiches by slicing them in half and placing them in a pita with spinach, feta cheese, and a slice of tomato.