When ready to cook, fill a high-sided saute pan or Dutch oven with enough canola oil to cover the chicken and heat to 350 degrees F.
Mix the yogurt with 2 to 3 tablespoons water in a small bowl. Mix together the rice flour and cornstarch in another bowl. Dredge the chicken first in the yogurt mixture, then in the rice flour mixture, shaking off any excess. Fry in the oil until golden brown and delicious, about 8 minutes, rotating chicken pieces so all sides are cooked. Transfer the chicken to a baking sheet fitted with a cooling rack to let any excess oil drain. Keep the oil hot.
Heat a wok or large saute pan over high heat. Add 2 tablespoons of the hot oil and swirl to coat the pan. When the oil is hot, add the garlic, scallions, chiles, ginger, onions and bell peppers and toss rapidly, cooking until translucent, about 2 minutes. Return the chicken to the wok and toss to combine. Transfer to a platter with rice. Add the potato slices into the hot oil and fry until golden brown and floating on top of oil, about 5 minutes. Blot on a paper-towel-lined plate and transfer to a serving vessel.