Bring a large saucepan of salted water to a boil over high heat. Add the rice and cook, stirring until tender, 25 to 35 minutes (depending on the rice blend).
Meanwhile, bring a separate saucepan of salted water to a boil over medium-high heat. Add the quinoa and cook until tender, about 12 minutes.
Drain the grains and rinse under cold water until cool; shake off the excess water.
Whisk the lime juice and zest, the peanut oil, sugar, 1 teaspoon salt, and pepper to taste in a large bowl. Add the rice mixture, mango, cucumber, jalapeno, scallions, cilantro and peanuts and stir to combine. Season with salt.
Photograph by Con Poulos
Courtesy of Food Network Magazine