Slice the chicken and mix with olive oil, tomato paste, Greek yogurt, lemon juice, and spices. Marinate for at least 30 minutes.
Cut the tops off the garlic heads, drizzle with olive oil and salt, wrap in foil, and bake with the chicken at 425°F for 25 minutes. Squeeze the roasted garlic into the chicken and toss.
Mix all tzatziki ingredients together and chill for 30 minutes.
Toss all salad ingredients together.
Fill warm pita or naan with tzatziki, chicken, and salad.
