I'm not sure how you arrive at that opinion. Take the example of Punjabi food. It's heavily based around ghee and dairy. Does anything in Thai cuisine use butte

I'm not sure how you arrive at that opinion. Take the example of Punjabi food. It's heavily based around ghee and dairy. Does anything in Thai cuisine use butter except European style pastries? The only major similarities I see uniting the national cuisines you listed (not regional ones) are things like curries and rice. The former arrived in Japan with European influence (where it's also common in colonial countries) and the latter isn't a feature common to all Asian cuisines (e.g. Mongolian).