I'm going to talk about the differences between north and south Indian food. North Indian food is what you would have had in your typical Indian restaurant in North America. It tends to have, they have a lot of roasted meats that are cooked in the Tandor. Tandori chicken would be an example. They also serve lovely rice dishes called Barianies. Kind of rice casseroles. You have a lot of flatbreads. Puries [SP], Chopanis [SP]. Those are eaten with thick, kind of mild curries.
In the south, rather than the flatbreads, they eat their main meal with rice. And their curries tend to be soupier. Much wetter. Which soaks nicely into the rice. And in the north, the whole climate is much cooler, and dryer, and there are plains for growing wheat, and grazing cattle. So dairy is a big ingredient. Gee [SP], clarified butter. Cream. Yogurt. Buttermilk. These are all things used to flavor and thicken their curries.
Whereas in the south, where it's much warmer and more tropical, coconut is the dominant ingredient. So coconut oil is what they use as a cooking medium. Coconut milk is what they thicken their curries with. As well as grated coconut meat. The north Indian curries tend to be a little milder. The south tends to be a little spicier, and a little more sour, too. So you have a kind of a hot, tangy, vibrant flavor profile in the south. And in the north you have a more toasty, mild, creamy flavor profile.
In the south, they use their spices ground into wet masalas [SP]. In the north, they dry roast their spices, and then grind them. Giving the curries a really nice roasted flavor. One way to think about the differences is, if you picture a map of India, and you draw a line across the middle, the northern part has a cooking that tastes more like middle eastern cooking. And the southern part has a cuisine that tastes more like southeast Asian cooking.
So they're very different. They're both very delicious.