Preheat oven to 450 degrees F. Line a sheet pan with parchment paper. Set aside.
In a large bowl, whisk together the garlic, oregano, paprika, salt, cumin, cinnamon, pepper, olive oil, lemon juice and zest.
Place the diced chicken in the bowl and toss to combine.
Spread in a single layer on the prepared sheet pan.
Bake for 20 minutes, or until the chicken is completely cooked through,
To serve, warm pita/naan in oven, about 3-4 minutes. Top warmed naan with chicken, romaine lettuce, tomatoes, red onion, cucumber and tzatziki sauce.