Cut mango into small pieces with skin intact. Grind 2 tablespoons of mustard and 3 red chilies in a mixer to semi coarse consistency.
Now,add mango and coconut to this mixture and grind again so that mango blends well and no chunks remain. Add curd and salt to this mixture and grind again to blend all the ingredients well. Transfer this mixture to a serving bowl.
To garnish, heat oil in a frying pan. when hot, put mustard seeds and let splutter.Tear the red chili into 3 pieces and put into the oil followed by curry leaves and turn off the heat. Pour this mixture on top of manga perikku.