Take a large sauté pan and put in Olive Oil. Heat oil then place chopped white onion, chopped garlic, salt and pepper and sauté until soft. Mix in 1 Cup of flour and stir until complete blended to form a light rue. Add chicken stock and a cup of white wine, bring to a boil then reduce heat and simmer. Once the stock starts to thicken, place a cup of chopped parsley into the pan and mix. When the contents turn a nice light green color, place the Snapper into the pan. Be sure there is enough of the mixture to cover at least half of the fish. If not, add more chicken stock and wine. Cook for 8-10 minutes on each side depending on the thickness of the fish making sure to be careful when turning not to break the fish. When finished, place the fish over a bed of rice and pour the green sauce over the fish.