Preheat the oven to 400° F.
Layer a baking sheet with parchment paper and spray the parchment with olive oil spray.
In a large bowl, combine the ground beef, grated onion, minced garlic, red wine vinegar, ouzo (if using), breadcrumbs, egg, cumin, oregano, salt and pepper. Mix with clean hands gently until all the ingredients are combined.
Shape and form the meatballs and place them onto the lined baking sheet.
Spray with olive oil cooking spray and cook for 25 to 30 minutes until the meatballs are brown and cooked through.
Meanwhile, prepare the orzo pilaf
Heat a large nonstick skillet over medium heat and add 1 tablespoon olive oil.
Saute diced onions and minced garlic for a few minutes, until soft.
Add the orzo and stir to mix. Add the broth, bring to a boil, then reduce the heat to a simmer and cover the pan for about 10 minutes until the orzo is cooked through. Add the chopped spinach, dill, olives and feta cheese to the skillet and stir to combine. Pour the lemon juice on top and top with the meatballs and serve.