Cut the cod loin into chunks, pat it dry with paper towels, and season with salt and pepper.
Heat a non-stick skillet to medium and add the olive oil.
Add the garlic cloves and let them cook for a couple of minutes, just until golden brown. Remove and reserve.
Place the cod loins, skin side down, in the oil and let it cook at low/med temperature, around 60ºC/140ºF (you are not frying the cod, it should cook in oil but slowly). You will cook them for around 7-8 minutes per side or until they are white on both sides and start to release the fat and collagen. You can use a spoon to cover them with hot oil while they continue cooking on one side.
Remove around half of the oil that’s left in the skillet and reserve. Add the fish broth and dried chilis and move the skillet vigorously until it starts to emulsify – instead of a liquid sauce, it will become kind of a soft jelly consistency.
Add the cod back to the skillet, season with salt and pepper, and top with fresh parsley.