Grate the pecorino Romano cheese and black pepper and place in a small mixing bowl.
Preheat the oven to the lowest setting possible: about 100°F or 40°C. Just before serving the pasta heat up the pear slices in the oven.
Bring a pot of salted water to a boil.
Use just enough salt so that the water tastes like the sea.
Cook the spaghetti until al dente, or according to package instructions.
Place the pears on a parchment paper lined baking sheet and put in the oven to reheat.
Whisk the cheese and black pepper together.
When the pasta is al dente use a pasta claw to scoop it out of the pot and into a serving dish.
Use a ladle to add pasta cooking water to the pepper and cheese mixture, one ladleful at a time.
Gently stir the water into the cheese – not vigorously please as the cheese will begin to clump!
Once the sauce is creamy – about like pancake, crepe or cake batter – pour it on top of the spaghetti.
Gently toss the spaghetti and cheese mixture together until creamy. If the pasta is too dry add a bit more pasta cooking water, by the ladleful.
Place the pear slivers decoratively on top of the pasta and serve.