Spanish omelette signed. Upon their release, these prisoners brought part of the culture of Alentejo to Spain, including many recipes, which featured a potato egg pie that evolved into the modern version of "tortilla". Spanish omelettes can range from authentic and carefully made seasoned preparations of raw potatoes of a variety carefully selected for best results, eggs, optional onions and good olive oil and nothing else, to nontraditional preparations with many additional ingredients. Some of the many additions to the base ingredients include green peppers, chorizo, courgette, aubergine, mushrooms, and diced ham. The "tortilla paisana" includes red pepper and peas. The tortilla
Vegetable oils as alternative energy Vegetable oils as alternative energy Vegetable oils are increasingly used as a substitute for fossil fuels. Vegetable oils are the basis of biodiesel, which can be used like conventional diesel. Some vegetable oil blends are used in unmodified vehicles, but straight vegetable oil needs specially prepared vehicles which have a method of heating the oil to reduce its viscosity and surface tension. Another alternative is vegetable oil refining. The availability of biodiesel around the world is increasing, although still tiny compared to conventional fossil fuel sources. There is significant research in algaculture methods to make biofuel from algae. Concerns have