Combine chicken pieces, garlic, olive oil, oregano, salt, black pepper and lemon juice in a large ziplock bag and mix until the chicken is evenly coated. Seal and refrigerate for 30 minutes, or up to 1 day.
Preheat broiler and place the rack in the middle. Place skewers on a large baking sheet, and broil for 6-8 minutes, turning once, until the chicken is cooked through and no longer pink inside.
Add chicken and desired toppings to pitas and serve while chicken is warm. Buon appetito!