Put about 2 teaspoons of the canned tuna oil in a frying pan, and sauté the chopped onion in it. Drain off the rest of the oil in the can.
Turn the heat down to low and add the ● ingredients. Mix well until the tofu is mashed finely. Add the cake flour little by little, mixing well so that no lumps form.
The mixture will become thick and hard to stir, but keep stirring until cooked through. Turn off the heat and stir in the black pepper. Transfer to a container and chill in the freezer or with ice packs.
Put the panko in a bowl, and drop spoonfuls of the Step 3 mixture into it. Coat each portion with panko while you form them into patties that are less than 6 cm in diameter.
Put a generous amount of olive oil in a frying pan, cook until browned on both sides, and they're done. Try the first one without adding any sauce to it.
If you are going to add sauce, I think ketchup and similar sauces fit well. I'm also into having these croquettes with wasabi-mayo-sauce (Recipe ID: 1743361).
Please also take a look at the sister recipe, "Sublime Non-Deep Fried Creamed Corn Tofu Croquettes" (Recipe ID: 1759100) too. They're sweet and sooo creamy and sublime.
Story Behind this Recipe
I wanted to make tasty croquettes without using meat or dairy products. The filling is really creamy, just like béchamel sauce.
In Step 3, stir constantly over low heat to cook the cake flour through, taking care not to let it burn. Since the tuna and soup stock flavor the filling well, it's best not to add salt. The croquettes are easier to form if you chill the filling well. The croquettes are very tender, so form them into small patties so that they won't fall apart when you hold them with chopsticks.