Ok this SOUNDS like its hard as theres a lot of ingredients, but its actually REALLY quick and easy. its just a matter of chucking stuff in a pan :)
1)boil water and place pasta in to cook
2) fry Mushrooms and onion- be generous with mushrooms as they shrink
3) add to pan pasta sauce, olives and additional things that you think would taste nice- be adventurous!! you can add a handful of nuts, tandori paste, garlic, all kinds of spices and herbs. GO FOR IT!! but make sure that you keep on tasting what your cooking.
4)when pasta is cooked, strain, put in a bowl and mix in sauce
5) add cheese- depending on the cheese, you can grate, crumble, slice etc.according to taste
smooth feta or goats cheese is brilliant with it, but you can just grate up some normal cheese and add that in.
if you dont have a jar of pasta sauce, you can easily make your own by getting a bottle of tomato sause (NOT KETCHUP...TOMATO SAUCE!) and adding spices and things like curry powder, paprika etc