Possibly the easiest, most satisfying pasta dish, ever.
1 lb spaghetti
2 cups shredded Kashkaval or Provolone
1 cup Bulgarian Feta
1 egg, beaten
1 1/2 tsp freshly ground black pepper
1 tsp salt
1/3 cup reserved pasta cooking liquid
Bring a large pot of salted water to a boil. Cook spaghetti until al-dente. Before draining the pasta, reserve 1/3 cup of the starchy cooking liquid. Drain the spaghetti and return to the pot.
Add the cheese and the cooking liquid to the pot. Mix and toss. Just before all the cheese has melted, add the egg, salt, and pepper to the pot and continue to toss.