If they're served with crushed rock sugar, usually while you're waiting for the bill after the meal, they're cumin seeds.lomuamart wrote:I think thet're carraway seeds. Helps digestion.
I think the main difference between the mainstream Thai food and the southern variety is that they use more spices down south. Although the basic ingredients are the same, you will find ginger, cumin, tumeric, mustard seeds, fennel, cloves and leaves from the curry tree will have been added.
As for the heat in the chilies, it varies according to the weather. They tend to get spicier in a hot, dry spell.