Rinse rice in a fine mesh strainer under cold running water until no longer cloudy. Transfer to a medium saucepan and cover with 2 1/2 cups water. Bring to a boil, cover, and reduce heat to low. Simmer for 15 minutes, remove from heat and let stand for at least 10 minutes, or until all liquid has evaporated.
Preheat oven to 250 degrees F (120 degrees C).
Season chicken with salt and garlic powder. Heat 2 tablespoons vegetable oil in a skillet over medium-high heat. Cook chicken, reducing heat when necessary, until no longer pink in center and juices run clear. Transfer to preheated oven to keep warm.
Place lettuce, cucumbers, onions, tomatoes, bell peppers, and cilantro together in a large mixing or serving bowl. Toss to combine. In another bowl, stir together the lime juice, fish sauce, sugar, and crushed red pepper until well blended and sugar is dissolved.
Remove chicken from oven, slice into thin strips, and drizzle with dressing. Divide salad and rice among serving plates, and top each with chicken slices. Dressing may also be served at the table and each salad dressed individually.
