Heat the oil in a medium sized frying pan until the oil just starts to shimmer.
Add the cassia bark. You should see little bubbles forming around it. Cook for about 30 seconds.
Stir in the garlic ginger paste and green chilies (optional). Cook until the garlic ginger paste stops sputtering.
Turn your heat down to medium low and add your spice mix. This is why you added 3 tablespoons of oil. You want to fry your spices in the oil. If you skimp on the oil you risk your spices sticking or burning. If your spices burn here you are starting over. Cook the spices for about 30 seconds.
Add the Indian hotel curry gravy. Stir it really well to get the oil to combine with the curry gravy. You want everything mixed together at this point. Bring to a simmer.
Cover loosely and cook for about 5 minutes.
Add 1/2 tsp of naga chili pickle and the coconut milk and stir. Taste. Decide if you want more naga pickle flavour and heat. Creep up on it. I love the taste of naga pickle but it does get pretty spicy fast so be careful.
Decide at this point whether you want the sugar or not. It's optional and it depends whether you like that little hint of sweetness in the background.
Add the naga chicken tikka. Continue to cook for about 1 minute to warm the chicken through.
Serve to your chili head friends.