Remove parsley leaves from stems (Some stems arefine, but definitely leave out the thick, tough stems. We want MOSTLY leaves)
Finely chop the parsley. You want some texture to the sauce, but you also want a balanced bite, without big chunks of one single ingredient.
Peel and mince your onion.
Peel and grate or mince your garlic.
Add parsley, onion, and garlic to a bowl, along with red chili flakes and dried oregano.
Add the extra virgin olive oil and vinegar to the bowl with the other ingredients.
Mix everything together and add salt to taste.