In a medium saucepan heat oil over high heat. Add onion and cook until tender but not browned, about 5 minutes. Add rice, stirring to coat in oil. Add stock and season to taste with salt and pepper. Bring to a boil, reduce heat to a simmer, cover and cook 10 minutes. Check rice, and if almost tender add shrimp, green onions, parsley, and more liquid, if necessary. Cook until shrimp are pink and rice is tender. Sprinkle with Creole seasoning before serving.