Quanto Basta or QB is just a
fancy way of saying "use your freaking
brain" when following a recipe.
QB means you get to be the judge of how much of an ingredient you need to add, based on your superhuman intuition and culinary skills.
It's like a little
game where you have to guess the right amount, and if you mess up, you can blame it on QB and say you were just following the recipe's instructions.
Easy peasy, right?