Cut the red part of the watermelon in cubes of around 4 by 4 cm. Remove the seeds.
Curry sauce
Take a hand full of the cubes and put them in a blender.
Add chili powder, kurkuma, koriander and a pressed (or very finely chopped) clove of garlic to the watermelon juice.
Heat some oil in a pan and roast the cumin seeds for half a minute and then add the watermelon juice. Turn the heat low and let it simmer for about 15 minutes or until the juice is reduced to about ⅔ of what it originally was.
Add some lime juice and cook for another minute.
Curry
Add the watermelon cubes and make sure they're all completely covered in the curry sauce. Let them simmer for another 4 minutes.
Let the curry cool off and if you want to, even put it in the fridge for a while. Personally I like this dish best slightly cold on a hot summer day!