Cook your pasta as directed on package. This can be done while cooking the sauce or before. You end up tossing the noodles in the sauce anyway. Dice onions to your preferred size, then place in a large oiled pan on high heat. Cool until starting to caramelized. Add olives, italian seasoning, and black pepper. Toss with onions and cook for two minutes. Then add the diced tomatoes (DON'T DRAIN! The liquid is used to help make the saucey part) and toss with the olives and onions. Add the sherry and let the liquid boil down. This can take between 5-10 minutes, depending on how high you set the heat. Once the liquid part is to a more sauce like consistency, add the alfredo and thoroughly combine. Add your pasta directly into the pan, turning the heat to medium-low, and toss the pasta with the sauce until full coated and mixed together. Serve alone, or with meat. It's a flexible recipe, and can have meat added to it (though cooking the meat before adding to the sauce is best).