Indian curry is different from Japanese curry because Japanese curry is thicker than Indian curry. We always eat it with not naan but rice. Since we can easily get the recipe of Indian curry on the internet, many people enjoy eating Indian curry in their homes. I also ate butter chicken curry at home. My wife cooked it after she looked into the recipe on the website called Cookpad. The butter curry included chicken, butter, onion, garlic, a can of tomato paste, and etc. Butter makes the taste not spicy but mild. Cookpad introduces not only recipes but also short video about how to cook. If you have an interest about the video, please try it.
Butter Curry : https://cookpad-video.jp/videos/4966