Start your good-sized pot of salted water on boil.
Drizzle olive oil into a warm sauté pan. Add the garlic cloves, sliced, the chili peppers, and 1-2 sprigs of fresh parsley. Heat on medium, and sauté for a few minutes. Turn off heat.
Meanwhile, add the pasta to the pot of salted boiling water. Cook for 1 minute less than the time indicated on the package, drain but keep a cup of the pasta cooking water.
Put the drained spaghetti into the pan with the garlic, oil, and chili peppers, add the white beans and stir for a minute. Add a 1/4-1/3 cup of the pasta water and the arugula, and sauté to wilt the arugula making sure the "sauce" coats the pasta. Salt to taste.
Dust with grated Parmigiano/Pecorino and serve.
Notes
The addition of the white beans and arugula beefs up a very simple Roman classic. You can also add tuna (or other zucchini) when you add the white beans for an even more substantial twist.