Set your oven to 450°F to preheat.
Prepare three baking sheets by lining them with parchment paper. Place a rack over one tray covered with parchment, brush it generously with olive oil for the meatballs.
In a spacious bowl, combine the ground beef, finely ground pita crackers, beaten egg, crumbled feta, minced garlic, half of the lemon juice and zest, chopped oregano, 3 tablespoons olive oil, 2 tablespoons finely minced red onion, 1 teaspoon salt, and 1 teaspoon pepper. Mix thoroughly using your hands but handle gently.
Shape the mixture into 24 evenly sized golf ball-sized meatballs using a small scoop if available.
Arrange the meatballs on the prepared rack or directly on a parchment-lined tray.
In another large bowl, add the chopped zucchini, cherry tomatoes, red peppers, Greek seasoning, remaining lemon juice and zest, 1/4 cup olive oil, Kalamata olives, plus the last teaspoon each of salt and pepper. Toss everything together until well coated.
Distribute the vegetable mix evenly over the other two baking sheets.
Place all trays into the oven and roast for 18 to 22 minutes. Check at 18 minutes and remove when the meatballs reach an internal temperature of 165°F and vegetables are tender.
Serve hot and enjoy this easy, delicious Mediterranean meal.