Place all the listed marinade ingredients (except chicken) in a large bowl and whisk to smooth. Add the chicken and combine well. Cover the chicken and marinate for at least 1 hour. You could marinate the chicken tikka upto 18 hours.
Cook the chicken tikka on medium-high heat in a skillet or on the grill until charred and smoky. Cut the cooked chicken tikka in small bite size pieces.
Preheat oven to 400F. Place garlic naan on a parchment paper lined baking sheet or a pizza pan if you have one.
Spread 2-3 tablespoon of pizza sauce on the naan.
Scatter shredded mozzarella chesse in a single layer to over all the pizza sauce.
Arrange the sliced red onion, green bell pepper and chicken tikka pieces over the cheese. Drizzle a bit of olive oil on top. Additionally, I like to scatter a handful of shredded cheese over the tikka.
Bake the naan pizzas for 8-10 minutes or until the cheese has melted.
Optionally, sprinkle some chaat masala on the warm pizzas for added punch.You could also add bit of chopped fresh cilantro on top. Slice and enjoy! I love to serve it with green chutney.