Remove any visible fat from the roast. Combine oregano, freshly grated ginger, 3/4 teaspoon salt and 1/2 teaspoon black pepper; rub over meat.
Spray a large skillet with cooking spray and heat over medium. Brown roast on all sides. Slice onions while roast browns.
Add roast and sliced onions to slow cooker.
Add 2 teaspoons of orange zest (using the oranges to served with the dish), 1 cup orange juice, sugar and soy sauce to a small bowl. Whisk together and pour over meat. Cover and cook for 8-10 hours on low (or 4-5 hours on high).
Cook rice according to package directions about 30 minutes before serving dinner (if cooked earlier, it will need reheating). While rice cooks, peel oranges; cut wedges in half and toss into a large salad bowl.
Thinly slice bell pepper and add to the bowl, along with tomatoes, lettuce, and feta cheese; toss to combine. Cover and refrigerate until ready to serve. Add your favorite dressing just before serving.
Remove roast from slow cooker. Drain juices into medium saucepan and skim off fat.
Add cornstarch and remaining 1/4 cup of orange juice to the saucepan and whisk to combine; cook over low heat until thickened and bubbly, stirring frequently (approximately 3-5 minutes).
Serve roast over rice, drizzled with sauce; serve salad on the side. (Each serving is 3oz meat, 1 cup salad, 1/2 cup rice).