Bring a pot of salted water to a boil. Once boiling, add the pasta to cook and give it a nice turn to keep from sticking together.
Meanwhile, in a small frying pan, add about a third cup of olive oil, hot pepper if you like spicy, and the garlic. Do not start frying.
Once the pasta has three minutes left to cook, start frying the garlic and oil over a medium flame, making sure to not let the garlic burn.
Once the pasta is done cooking, reserve a cup of the water before draining the pasta. Add half cup of pasta water and the pasta back into the pot.
Raise the flame to medium/high to continue frying the garlic and oil. At the same time, add the arugula into the pasta pot and stir until just wilted, about one minute. If needed, add in the remaining pasta water.
Remove the hot pepper from the garlic and oil pan and pour the garlic and oil into the pasta and arugula pot. Mix together and enjoy. Salute and cin cin!