Drain the cans of tuna into a fine sieve with a bowl underneath, gently flake the tuna and set aside
Heat a large fry pan with a medium heat add in 3 tbsp (45 ml) of the drained oil from the canned tuna
After a couple of minutes add in the onion finely chopped and the garlic roughly chopped, mix continuously, after 3 minutes and the onion is translucent, add in the drained tuna, chopped parsley and season with sea salt & black pepper, quickly mix together, then add in the flour and continue to mix for 2 minutes, then slowly add in the milk while mixing continuously, once all the milk has been added, continue to mix until you end up with a thick paste-like texture, about 5 minutes, then transfer the mixture into a bowl and cover with saran wrap
Meanwhile, crack the eggs into a bowl, season with sea salt & black pepper and whisk together, add the bread crumbs into a separate bowl
Once the tuna mixture is cool enough to handle, start shaping the croquettes, in the size of a small egg (if your mixture is too wet, just add in some bread crumbs and mix until you get a firm texture), then coat each one in the egg wash and finally in the bread crumbs
Heat a large fry pan with a medium heat and add in the sunflower oil
Once it´s nice and hot but not smoking, about 5 to 6 minutes, add in the croquettes, all in a single layer, fry for 1 minute per side or until golden fried all around, then transfer into a dish with paper towels
Serve piping hot or warm, garnished with fresh parsley, enjoy!