|Heat margarine in pan until melted. Mix in flour, stirring with a whisk until smooth. Return to heat and slowly brown to light color. Add paprika, salt, pepper and cayenne. Remove from heat and add onions, green pepper and garlic. Cook slowly for 5 minutes, stirring constantly. remove heat again; add lemon juice, Worcestershire, oysters and their liquid. Stir well. Pour into a 13 x 9-inch baking dish. Sprinkle with crumbs and bake at 400 degrees F for 30 minutes.