Place the skinned fish fillets in a cutting board and remove their small bones. Now, slash each of them in half crosswise and cut into elongated and thin strips. Place the fish slices in a large bowl and top with the 300 ml of rice vinegar. Toss the slices to coat them with the liquid and leave it for about one hour to marinate properly.
Note: It is better to perform this step in advance so that the fish strips get enough time to marinate.
Take another bowl and pour in the remaining 200ml of rice vinegar. Now, add in the finely sliced onions, white sugar and the salt. Stir the mixture until the sugar and salt dissolve. Set the mixture aside at room temperature for approximately 30 minutes to soak well.
In the mean time, crush the raw peanuts finely and place them in a medium non-sticking frying pan. Set the pan on the stove with low heat and dry-fry the crushed peanuts for about 2 to 3 minutes or until lightly browned. Remove the frying pan from heat and set aside until the roasted peanuts are cool to handle.
Take another frying pan and place the white rice in it. Now, place the pan on stove and toast the rice for about 3 to 4 minutes until all rice grains are golden brown. Remove the roasted rice from heat and crush them with the help of the bottom of a large spoon.
Get back to the marinated fish strips at the end of one hour and remove them from the vinegar mixture. Place them in another large salad bowl. Scatter some finely chopped mint and chili all over the fish slices.
Now, sprinkle the well-crushed toasted peanuts and rice.
Toss the overall ingredients to coat them finely.
Garnish the salad with the remaining fresh mint and chili slices. Serve and enjoy!