Shred the cod fillets, removing any bones and skin.
Cut the potatoes, carrots, turnips, and Portuguese cabbage into small pieces.
In a large pot, sauté the onion, followed by the garlic.
Add the Portuguese cabbage, carrots, and potatoes, and let them fry a little in the olive oil.
Stir in the shredded cod, mixing well so everything is evenly combined.
Layer the ingredients so they are well mixed and balanced.
Check the seasoning and adjust with a little more salt if needed. If desired, add ground cumin.
If the sauté looks too dry, add some cod cooking water and more olive oil.
Stir everything until the ingredients are well combined and lightly fried.
Add the hard-boiled eggs, sliced into rounds or halves, reserving a few for garnish.
Transfer to a large serving platter and top with the reserved egg slices.