Heat a large pot (crockpot size is best) with water and a pinch of salt over medium-high heat.
Once water is boiling add in the spaghetti. Do not break the noodles. Place them in the pot. If necessary, twist them as you put them in so that they will all be covered with the water.
Heat a nonstick skillet over medium heat while the pasta is cooking. Add the guanciale (pork) once the pan is warm. The meat should sizzle a little when it is placed in the pan.
Cook the meat for 5 minutes or until tender.
Once the meat is tender, add 1 ladle (about ½ cup) of pasta water. Put a lid on the meat and let it simmer in the pasta water.
After a few minutes (2-3), add another ladle of pasta water. Place the lid back on the meat and continue to simmer over medium-low heat.
Once the pasta has been cooking for 10 minutes, scoop out 1 cup of pasta water and drain the rest.
Add the spaghetti noodles to the pan with the guanciale and sauce. Toss the noodles, sauce, and meat together. Add more pasta water if the sauce is too thick or if there is not enough.
Turn off the heat and remove the pan from the burner.
Toss the pasta, sauce, and meat with the cheese until a creamy sauce is created.
Serve the pasta with fresh grated Pecorino Romano cheese and pepper.