Peel onion and garlic and chop finely. Heat the olive oil in a saucepan and braise both in it. Add the spinach (not defrosted) and some water and cook for about 10 minutes. Season to taste with herb salt and nutmeg.
Thaw the fish fillet and season with a little lemon salt. Mix the sesame and chia on a plate and coat the moist fish with it (because the fish is moist, the breading also holds). Heat the coconut oil in a pan and fry the fish in it. Each side approx. 2 - 3 minutes.