Cut the onion into half rings, the thinner the better! Finely chop the parsley. Squeeze the juice from half a lemon, pour soy sauce over it.
Mix, finely chop 2 cloves of garlic (do not use a garlic press), put the garlic on top of the onion.
Take the mussels, defrost, rinse under running water and put in a saucepan with salted water, bring to a boil, let it boil for 2 minutes and drain.. spread the mussels on top of the onion and garlic (do not mix!!)
Heat the oil in a frying pan. Finely chop the remaining 2 cloves of garlic and throw the garlic into the heated oil, without letting the garlic fry, very quickly pour oil over our mussels... and mix thoroughly. Sprinkle with chili pepper and enjoy a great beer snack!!