Preheat oven to 450 degrees F.
Line three baking sheets with parchment paper. Place a cooling rack on top of one of the baking sheets covered in parchment for the meatballs to drain and brush liberally with olive oil. Set aside.
In a large bowl, mix lean ground beef, pita cracker crumbs, beaten egg, finely crumbled feta (I use a mini food processor for the cheese and pita crumbs), minced garlic, 1/2 of the lemon juice (juice of 1/2 a lemon), 1/2 of the lemon zest, fresh oregano finely chopped, 3 tbsp olive oil, 2 tbsp finely minced red onion, 1 tsp salt and 1 tsp pepper.
Mix well, using your hands to thoroughly combine.
Form meatballs into 24, evenly sized, balls. They should be about the size of a golf ball or slightly larger. I use a small scoop for this.
Place meatballs onto the baking sheet with rack (or just place them directly on the parchment-lined pan), and set aside while you prep the vegetables.
In another large bowl, combine chopped vegetables, Greek seasoning blend, remaining lemon juice and zest (of 1/2 the lemon), 1/4 cup olive oil, olives, tomatoes and remaining 1 tsp of salt and 1 tsp pepper. Toss to blend.
Spread vegetables onto the remaining two baking sheets.
Bake meatballs and vegetables for 18-22 minutes. I start checking at 18 minutes and pull them when the meatballs are 165 degrees F.