Cook the bacon in a cold large skillet over medium heat until golden brown.
Once the fat is rendered, add the butter and cook the bacon until golden brown.
Add the onions and sauté them until transparent. (Make sure the onions are finely chopped.)
Add the garlic and sauté for a minute.
Add the cassava flour and stir continuously to avoid it burning. Add small amount of oil if needed.
Add the olives and hard boiled egg if desired.
Add salt and pepper to taste, and once the farofa is evenly toasted, remove it from the heat.
Add the parsley and chives and mix well.
Put the farofa in a serving bowl and serve at room temperature.