Combine fish, 1/2 cup flour, oyster sauce, sweet chili sauce, fish sauce, brown sugar, cilantro, green onions, and egg in a food processor. Process until well combined. Refrigerate for 30 minutes.
Shape mixture into patties, and dust with flour.
Pour enough oil into a heavy skillet to fill the pan with 1/2 inch of oil. Heat over medium-high heat until hot. Fry fish cakes for 8 minutes, turning once, or until golden brown.