1. In a bowl, mix together the potatoes, shallots, tuna, garlic, 1/4 cup plain flour and 1 egg until combined. Roll into 15, 8cm x 2cm log shapes and roll in the remaining flour. Place into the refrigerator for 2 hours to set.
  2. Place 2 eggs into one bowl and lightly whisk. Place the bread crumbs into another bowl. Roll the croquettes in the egg mixture, let the excess drip off and then roll in the breadcrumbs and transfer to a tray.
  3. In a pot or deep fryer add 2L or more of oil and heat to 180°C. Place croquettes into the hot oil and cook until they are evenly golden. Remove from the pan and drain on paper towel.
  4. Mix the diced avocado with some thinly sliced shallots or your favourite herbs and serve over the croquettes.