Greek Chicken Meatballs with Eggplant and Zucchini in Pita

• 1 zucchini, sliced lengthwise into 4 long slices
• ½ of small eggplant, cut lengthwise and then in ¼-inch slices
• 1 pound ground chicken or turkey
• ½ cup finely chopped onion
• 1 cup soft breadcrumbs
• 1 egg
• 1 teaspoon salt
• ¼ teaspoon pepper, plus more to taste
• 2 tablespoon parsley, chopped
• 1 tablespoon fresh mint, chopped
• Extra-virgin olive oil
• Dried oregano
• 2-4 whole-grain pita bread rounds, cut in half
• Shredded lettuce
• 1-2 tomatoes, diced
• ½ cup feta cheese
• Tzatziki sauce (store-bought or recipe below)

Tzatziki Sauce:

• 1/3 English cucumber, peeled and diced
• 1 cup Greek yogurt
• 2 cloves garlic, minced
• 2 tablespoons fresh dill
• 1 tablespoon fresh-squeezed lemon juice
• ¼ teaspoon salt
• Hefty pinch of pepper