Cook the rice and the quinoa according to package directions; let cool. In a large bowl, toss the rice, quinoa, bell pepper, tomatoes and scallions. In a small bowl, whisk 1/4 cup oil, the vinegar, 1 1/2 tbsp. ginger and the lemon juice and garlic. Toss with the salad; season with salt and pepper.
Heat a grill or grill pan over medium. Cover with foil to prevent sticking. In a small bowl, whisk 3 tbsp. oil, the remaining 1 1/2 tbsp. ginger and the honey. Season the pork and grill, turning occasionally, until an instant-read thermometer inserted into the center registers 145 degrees , 22 to 25 minutes. Brush with half the honey mixture during the last 5 minutes of grilling. Let rest 10 minutes. Brush with the remaining honey mixture. Cut on an angle into 1/3-inch-thick slices. Serve over the salad.