Cook the spaghetti in plenty of salted water until just barely al dente. I usually shave off 3 minutes from the package directions. Heat the oil in a large pan and toast the black pepper for a couple of minutes over medium low heat. When the pasta is done, pull it out with tongs and into the pepper pan. A little of the cooking water will go along with the pasta. Add in the butter and lemon juice and toss thoroughly with the cheese, a handful at a time and tossing to coat the pasta evenly between each addition. Add in ladles of pasta water as needed to create a creamy smooth sauce. I think I must have added at least a cup. Toss in the parsley at the end.