Cooking Pro: Mother Sauces

Especially when learning to cook, it is very easy to be tempted to simply go day after day just finding a new recipe, going to the store, buying the ingredients and then blindly and diligently following the instructions. But what about the day when you are missing just a pinch of that one spice? What about the day when you have to work with the ingredients you have in your fridge and have no ideas how to combine them?