Instructions

  1. Melt the butter in a small saucepan over medium heat. Add the onion and cook until soft. Stir in the flour and cook for 1 minute.
  2. Drain the tuna and measure the liquid. Add enough milk to equal 1/4 cup liquid. Whisk into flour mixture, cooking until thickened.
  3. Season with salt and pepper and stir in tuna and olives. Refrigerate the mixture until cold.
  4. Shape 1/4 cup of the mixture into a patty. Coat with flour, then egg, then bread crumbs.
  5. Fry in a little hot oil in a skillet, turning once or twice, until crisp and golden outside, a total of about 6 minutes per side.