Add the rice, lemongrass and chili to a nonstick skillet and toast over medium-low heat, shaking the pan occasionally until the rice is toasted and golden brown, about 15 minutes.
Remove from heat and let cool completely. Then add the toasted rice mixture to the bowl of a food processor, spice grinder or mortar and pestle, with the lime zest, sugar, salt and garlic powder. Grind until the texture of sand. Strain out any large pieces of lemongrass.
Remove to a bowl or container then cover and store until ready to use, for up to 1 week.
For the wings:
Toss the wing in the fish sauce and rice vinegar, tossing to combine. Remove to a large bowl, cover and refrigerate for at least 1 hour and up to overnight.
When ready to cook the wings, let them stand at room temperature for 30 minutes, so that the wings cook evenly. Pat dry with paper towels.
Fill a large heavy-bottomed pot with enough oil to reach 2-inches up the side of the pot. Heat oil to 375°F (190ºC). Add the cornstarch to a shallow mixing bowl.
When the oil is hot, work in batches and dredge the wings in cornstarch shaking off the excess. Lower the wings into the oil and fry, turning occasionally, until the chicken is cooked through and the outside is golden brown, about 10 minutes.
Transfer to a wire rack set over a baking sheet to drain. Place the rack in the oven to keep warm and repeat with the remaining wings.
Once all wings have been fried add to a large bowl and squeeze the lime juice over the top followed by the rice blend. Toss to coat evenly.
Spread on a platter and top with the green onion, cilantro and mint and serve.