Stir together the soy sauce, vinegar, and brown sugar in a small bowl. Set aside.
Heat the oil in a large skillet or wok over medium-high heat until hot. Add the shrimp and cook 2-3 minutes or until pink. Remove from the pan and set aside.
Add sesame oil to the pan. Add the onion, garlic, and ginger and cook 3 minutes or until tender. Add the frozen vegetables and cook until tender. Push the ingredients to one side and add the beaten eggs. Cook until the eggs are scrambled.
Add the rice to the pan and cook until thoroughly heated through. Stir in the chicken, shrimp, and sauce. Cook until hot, stirring frequently. Remove the rice to serving bowls and garnish with green onions.