1. Slice the bacon into 1-2cm squares and fry them. Set aside.
2. Boil the spaghetti until al dente.
3. Using the remaining fat from the bacon, add some oil if necessary to fry the mushrooms and zucchini. You know it's done when the mushroom turns colour. Add olives and 2 T of spaghetti water.
4. Mix the sour cream and tomato sauce in a small bowl and pour the mixture into the pan. Mix it in.
5. When the pasta is done, drain it well and add to the pan. Mix well.
6. Serve and top with the bacon and some parsley.