In a resealable plastic bag mix yogurt and tandoori paste together. Add chicken, squish it around until everything is coated. Place in the fridge for at least an hour.

Preheat oven to 400 degrees. In a skillet over a low heat, heat the olive oil. Add the onion. Stirring often, allow the onions to become soft, golden brown and caramelized, about 30 minutes. Remove the onions, and set aside.

Turn up the heat on the pan to medium-high, and add the chicken (including the marinade). Cook until the chicken is done, and some of the sauce reduces. Remove the chicken, and set aside.

Lay the Naan bread on baking sheets. Spread the chicken over the bread, and top with the onions. Sprinkle on the cheese. Bake for 10 to 12 minutes, until the cheese is melted. To serve sprinkle with cilantro.